{"id":9745,"date":"2026-10-13T18:27:41","date_gmt":"2026-10-13T09:27:41","guid":{"rendered":"https:\/\/now0930.pe.kr\/wordpress\/?p=9745"},"modified":"2026-10-13T18:27:43","modified_gmt":"2026-10-13T09:27:43","slug":"lessons-in-industrial-instrumentation-chapter-20","status":"publish","type":"post","link":"https:\/\/now0930.pe.kr\/wordpress\/lessons-in-industrial-instrumentation-chapter-20\/","title":{"rendered":"Lessons In Industrial Instrumentation, Chapter 20"},"content":{"rendered":"\n<div class=\"chapter19-wide\">\n\n  <h1>Chapter 20. Level Measurement<\/h1>\n\n  <div class=\"subtitle\">\n    Displacement \u00b7 Echo \u00b7 Ultrasonic \u00b7 Radar \u00b7 GWR \u00b7 Laser \u00b7 Magnetostrictive \u00b7 Weight \u00b7 Capacitive \u00b7 Radiation \u00b7 Stilling Well\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4 Displacement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Displacement \ubc29\uc2dd\uc740\n      \uc720\uccb4\uac00 \ubb3c\uccb4\uc5d0 \uac00\ud558\ub294 \ubd80\ub825(Buoyant Force)\uc744 \uc774\uc6a9\ud558\uc5ec\n      Level\uc744 \uce21\uc815\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \uc561\uc704\uac00 \uc99d\uac00\ud560\uc218\ub85d Displacer\uac00 \uc720\uccb4\uc5d0 \ub354 \ub9ce\uc774 \uc7a0\uae30\uace0,\n      \ubb3c\uccb4\uc5d0 \uc791\uc6a9\ud558\ub294 \ubd80\ub825\uc774 \uc99d\uac00\ud55c\ub2e4.\n      \ub530\ub77c\uc11c \uc13c\uc11c\uac00 \uac10\uc9c0\ud558\ub294 \ubb3c\uccb4\uc758 \uac89\ubcf4\uae30 \ubb34\uac8c\ub294 \uac10\uc18c\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      F<sub>B<\/sub> = \u03b3V\n    <\/div>\n\n    <div class=\"formula\">\n      \u03b3 = \u03c1g\n    <\/div>\n\n    <ul>\n      <li>F<sub>B<\/sub> : \ubd80\ub825<\/li>\n      <li>\u03b3 : \uc720\uccb4\uc758 \ube44\uc911\ub7c9<\/li>\n      <li>\u03c1 : \uc9c8\ub7c9 \ubc00\ub3c4<\/li>\n      <li>g : \uc911\ub825\uac00\uc18d\ub3c4<\/li>\n      <li>V : \uc720\uccb4\uc5d0 \uc7a0\uae34 \uccb4\uc801<\/li>\n    <\/ul>\n\n    <div class=\"memory\">\n      <strong>\n        Level \u2191 \u2192 \uc7a0\uae34 \uccb4\uc801 V \u2191 \u2192 \ubd80\ub825 F<sub>B<\/sub> \u2191\n        \u2192 \uac89\ubcf4\uae30 \ubb34\uac8c \u2193\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4.1 Displacer\uc758 \uc555\ub825\uacfc \ubc00\ub3c4 \uc601\ud5a5<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc6a9\uae30 \ub0b4\ubd80\uc758 Static Pressure\ub294\n      Displacer Level \uce21\uc815 \uc815\ud655\ub3c4\uc5d0 \uc9c1\uc811\uc801\uc778 \uc601\ud5a5\uc744 \uac70\uc758 \uc8fc\uc9c0 \uc54a\ub294\ub2e4.\n    <\/p>\n\n    <p>\n      \ubc18\uba74 \uc720\uccb4 \ubc00\ub3c4 \ubcc0\ud654\ub294\n      \ubd80\ub825 \uc790\uccb4\ub97c \ubcc0\ud654\uc2dc\ud0a4\ubbc0\ub85c \uc911\uc694\ud55c \uc624\ucc28 \uc694\uc778\uc774 \ub41c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      F<sub>B<\/sub> = \u03c1gV\n    <\/div>\n\n    <div class=\"formula\">\n      \u03c1 \ubcc0\ud654\n      \u2192\n      F<sub>B<\/sub> \ubcc0\ud654\n      \u2192\n      Level \uce21\uc815\uac12 \ubcc0\ud654\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        Displacer\uc5d0\uc11c\ub294 Pressure\ubcf4\ub2e4 Density \ubcc0\ud654\uac00 \ud575\uc2ec \ubcc0\uc218\uc774\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4.2 \uc124\uce58 \uad6c\uc870<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Displacer\ub294 \uc678\uc7a5 Chamber\ub97c \uc0ac\uc6a9\ud558\ub294 \ubc29\uc2dd\uacfc\n      Tank \ub0b4\ubd80\uc5d0 \uc9c1\uc811 \uc124\uce58\ud558\ub294 Cageless \ubc29\uc2dd\uc73c\ub85c \uad6c\uc131\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <pre>\n      Cage Type\n\n      Tank\n       \u2502\n       \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Cage\n       \u2502               \u2502\n       \u2502           Displacer\n       \u2502               \u2502\n       \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518\n\n\n      Cageless Type\n\n      Tank\n       \u2502\n       \u2502\n       \u2502     Displacer\n       \u2502        \u2502\n       \u2502        \u2502\n       \u2502        \u2502\n       \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2534\u2500\u2500\u2500\u2500\u2500\u2500\n    <\/pre>\n\n    <p>\n      \uc124\uce58 \uc2dc Process Pressure\uac00\n      \uacc4\uce21 \uc624\ucc28\ub85c \uc9c1\uc811 \uc791\uc6a9\ud558\uc9c0 \uc54a\ub3c4\ub85d \ud558\uace0,\n      Process Noise\uc758 \uc601\ud5a5\uc744 \uc5b5\uc81c\ud574\uc57c \ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4.3 Calibration<\/h2>\n\n  <div class=\"card\">\n\n    <h3>Wet Calibration<\/h3>\n\n    <p>\n      \uc2e4\uc81c \uc720\uccb4\ub97c \uc0ac\uc6a9\ud558\uc5ec\n      Displacer\uac00 100% \uc7a0\uae34 \uc0c1\ud0dc\uae4c\uc9c0 \ubcc0\ud654\uc2dc\ud0a4\uba74\uc11c\n      \uc218\ud589\ud558\ub294 \uc2b5\uc2dd \uad50\uc815 \ubc29\uc2dd\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      \uc2e4\uc81c \uc720\uccb4 \uc0ac\uc6a9\n      \u2192\n      0% ~ 100% Immersion\n      \u2192\n      Calibration\n    <\/div>\n\n    <h3>Dry Calibration<\/h3>\n\n    <p>\n      \uc2e4\uc81c \uc720\uccb4\ub97c \uc0ac\uc6a9\ud560 \uc218 \uc5c6\ub294 \uacbd\uc6b0\n      0% \uc0c1\ud0dc\uc640 \uc678\ubd80\uc5d0\uc11c \uac00\ud558\ub294 \uad50\uc815\uc6a9 \ud798\uc744 \uc774\uc6a9\ud558\uc5ec\n      \ubd80\ub825 \ubcc0\ud654\ub97c \ubaa8\uc0ac\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      \uc2e4\uc81c \ubd80\ub825\n      \u2194\n      \uc678\ubd80\uc5d0\uc11c \uac00\ud558\ub294 Calibration Force\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4.4 Torque Tube<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \ubc00\ud3d0\ub41c Process \ub0b4\ubd80\uc758 Displacer \ubb34\uac8c \ubcc0\ud654\ub97c\n      \uc678\ubd80 Transmitter\ub85c \uc804\ub2ec\ud558\uae30 \uc704\ud574\n      \uae30\ubc00\uc744 \uc720\uc9c0\ud558\uba74\uc11c \ud798\uc744 \uc804\ub2ec\ud558\ub294 \uad6c\uc870\uac00 \ud544\uc694\ud558\ub2e4.\n    <\/p>\n\n    <h3>Torque Tube<\/h3>\n\n    <p>\n      Displacer\uc758 \ud798 \ubcc0\ud654\ub97c\n      Torque Tube\uc758 \ube44\ud2c0\ub9bc \uac01\ub3c4\ub85c \ubcc0\ud658\ud558\uc5ec \uc804\ub2ec\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Buoyant Force \ubcc0\ud654\n      \u2192\n      Apparent Weight \ubcc0\ud654\n      \u2192\n      Torque Tube \ube44\ud2c0\ub9bc\n      \u2192\n      Transmitter\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4.5 \ud798 \uc804\ub2ec \ubc29\uc2dd<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\ubc29\uc2dd<\/th>\n          <th>\uc6d0\ub9ac<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>Torque Tube<\/strong><\/td>\n          <td>\ud798 \ubcc0\ud654\ub97c \uad00\uc758 \ube44\ud2c0\ub9bc \uac01\ub3c4\ub85c \uc804\ub2ec<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Magnetic Coupling<\/strong><\/td>\n          <td>\ube44\uc811\ucd09 \uc790\uae30 \uacb0\ud569\uc73c\ub85c \ubcc0\uc704 \uc804\ub2ec<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Bellows<\/strong><\/td>\n          <td>\uc555\ub825\uc744 \uae30\ubc00 \uad6c\uc870\ub85c \ucc28\ub2e8\ud558\uace0 \ubd80\ub825\uc5d0 \uc758\ud55c \ud798\ub9cc \uae30\uacc4\uc801 \ubcc0\ud615\uc73c\ub85c \uc804\ub2ec<\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4.6 Displacer Interface Measurement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Displacer\ub294 \ube44\uc911\uc774 \uc11c\ub85c \ub2e4\ub978\n      \ub450 \ube44\ud63c\ud654\uc131 \uc561\uccb4\uc758 Interface \uce21\uc815\uc5d0\ub3c4 \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <p>\n      Interface \uce21\uc815\uc744 \uc704\ud574\uc11c\ub294\n      Displacer \uc804\uccb4\uac00 \ub450 \uc561\uccb4\uc5d0 \uac78\uccd0\n      \uc644\uc804\ud788 \uc7a0\uaca8 \uc788\uc5b4\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <pre>\n          Upper Liquid\n      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n           \u2502\n           \u2502 Displacer\n           \u2502\n      -----\u253c---------- Interface\n           \u2502\n           \u2502\n      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n          Lower Liquid\n    <\/pre>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.4.7 Interface\uc758 \ucd1d \ubd80\ub825<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Displacer \uc77c\ubd80\uac00 \uc0c1\ubd80 \uc561\uccb4\uc5d0,\n      \ub098\uba38\uc9c0\uac00 \ud558\ubd80 \uc561\uccb4\uc5d0 \uc7a0\uaca8 \uc788\ub294 \uacbd\uc6b0\n      \ucd1d \ubd80\ub825\uc740 \uac01 \uc561\uccb4\uac00 \ub9cc\ub4dc\ub294 \ubd80\ub825\uc758 \ud569\uc774 \ub41c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      F<sub>B<\/sub>\n      =\n      \u03b3<sub>1<\/sub>V<sub>1<\/sub>\n      +\n      \u03b3<sub>2<\/sub>V<sub>2<\/sub>\n    <\/div>\n\n    <p>\n      \uade0\uc77c\ud55c \ubc18\uc9c0\ub984 r\uc744 \uac16\ub294 \uc6d0\ud1b5\ud615 Displacer\ub77c\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      F<sub>B<\/sub>\n      =\n      \u03c0r\u00b2\n      (\n      \u03b3<sub>1<\/sub>l<sub>1<\/sub>\n      +\n      \u03b3<sub>2<\/sub>l<sub>2<\/sub>\n      )\n    <\/div>\n\n    <div class=\"formula\">\n      l<sub>1<\/sub> + l<sub>2<\/sub> = L\n    <\/div>\n\n    <p>\n      \u03b3<sub>1<\/sub>, \u03b3<sub>2<\/sub>\uc640\n      \uc804\uccb4 \uae38\uc774 L\uc744 \uc54c\uace0 \uc788\uc73c\ubbc0\ub85c\n      \ub450 \uc2dd\uc744 \uc774\uc6a9\ud558\uc5ec Interface \uc704\uce58\ub97c \uacb0\uc815\ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5 Echo-based Level Instruments<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Echo \ubc29\uc2dd\uc740 \ud30c\ub3d9\uc744 \ubc1c\uc0ac\ud55c \ub4a4\n      \uacbd\uacc4\uba74\uc5d0\uc11c \ubc18\uc0ac\ub418\uc5b4 \ub3cc\uc544\uc624\ub294 \uc2e0\ud638\uc758\n      Time-of-Flight\ub97c \uce21\uc815\ud558\uc5ec Level\uc744 \uad6c\ud55c\ub2e4.\n    <\/p>\n\n    <pre>\n        Sensor\n          \u2502\n          \u2502  Transmit\n          \u25bc\n      ~~~~~~~~~~~~~~~\n          Medium\n      ~~~~~~~~~~~~~~~\n          Surface\n          \u25b2\n          \u2502  Echo\n          \u2502\n        Sensor\n    <\/pre>\n\n    <div class=\"formula\">\n      Transmit\n      \u2192\n      Reflection\n      \u2192\n      Echo\n      \u2192\n      Time-of-Flight\n      \u2192\n      Distance\n      \u2192\n      Level\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.1 Echo \ubc29\uc2dd\uc5d0\uc11c Speed\uc758 \uc911\uc694\uc131<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Echo \ubc29\uc2dd\uc5d0\uc11c\ub294 \ud30c\ub3d9\uc758 \uc804\ud30c \uc18d\ub3c4\uac00\n      \uac70\ub9ac \uacc4\uc0b0\uc758 \ud575\uc2ec \ubcc0\uc218\uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \uc774\ub294 Hydrostatic Level\uc5d0\uc11c\n      \uc720\uccb4\uc758 Density\uac00 \uc911\uc694\ud55c \uac83\uacfc \uac19\uc740 \uad00\uacc4\ub85c \uc124\uba85\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Echo Method\n      \u2192\n      Speed\uac00 \ud575\uc2ec\n    <\/div>\n\n    <div class=\"formula\">\n      Hydrostatic Method\n      \u2192\n      Density\uac00 \ud575\uc2ec\n    <\/div>\n\n    <p>\n      Gas \uc870\uc131, \uc555\ub825, \uc628\ub3c4 \ub4f1\uc758 \ubcc0\ud654\ub85c\n      \ud30c\ub3d9 \uc18d\ub3c4\uac00 \ub2ec\ub77c\uc9c0\uba74 Level \uc624\ucc28\uac00 \ubc1c\uc0dd\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.2 Ultrasonic\uacfc Radar\uc758 Speed<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\uad6c\ubd84<\/th>\n          <th>Ultrasonic<\/th>\n          <th>Radar<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>\ud30c\ub3d9<\/strong><\/td>\n          <td>Sound Wave<\/td>\n          <td>Microwave<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>\uc18d\ub3c4 \uc601\ud5a5<\/strong><\/td>\n          <td>\ub9e4\uc9c8 Density \uc601\ud5a5 \ud07c<\/td>\n          <td>Permittivity \uc601\ud5a5<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>\uae30\uccb4 \uc870\uac74 \uc601\ud5a5<\/strong><\/td>\n          <td>\uc628\ub3c4\u00b7\uc870\uc131\uc5d0 \ub530\ub978 \ubcc0\ud654 \ud07c<\/td>\n          <td>\u03b5<sub>r<\/sub> \u2248 1\uc774\ubbc0\ub85c \uc0c1\ub300\uc801\uc73c\ub85c \ubcc0\ud654 \uc791\uc74c<\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.3 Echo \ubc29\uc2dd\uc758 4\ub300 \uc81c\uc57d<\/h2>\n\n  <div class=\"card\">\n\n    <ol>\n      <li>\n        <strong>Foam<\/strong><br>\n        Foam\uc774 \uc2e0\ud638\ub97c \ud761\uc218\ud558\uac70\ub098 \ub09c\ubc18\uc0ac\ud558\uc5ec\n        Echo\uac00 \uc57d\ud574\uc9c0\uac70\ub098 \uc798\ubabb \uac80\ucd9c\ub420 \uc218 \uc788\ub2e4.\n      <\/li>\n\n      <li>\n        <strong>\ubd88\uba85\ud655\ud55c Interface<\/strong><br>\n        Emulsion \ub4f1 \uacbd\uacc4\uac00 \ub69c\ub837\ud558\uc9c0 \uc54a\uc740 \uacbd\uc6b0\n        Liquid-Liquid Interface \ud310\ubcc4\uc774 \uc5b4\ub835\ub2e4.\n      <\/li>\n\n      <li>\n        <strong>Tank \ub0b4\ubd80 \uc7a5\uc560\ubb3c<\/strong><br>\n        Pipe, Agitator Blade \ub4f1\uc774\n        False Echo\ub97c \ub9cc\ub4e4 \uc218 \uc788\ub2e4.\n      <\/li>\n\n      <li>\n        <strong>Dead Zone<\/strong><br>\n        Sensor \uc9c1\ud558\ubd80\uc758 \ub9e4\uc6b0 \uac00\uae4c\uc6b4 \uc601\uc5ed\uc740\n        \uc1a1\uc218\uc2e0 \uc804\ud658 \ud2b9\uc131 \ub54c\ubb38\uc5d0 \uce21\uc815\ud560 \uc218 \uc5c6\ub2e4.\n      <\/li>\n    <\/ol>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.4 Ultrasonic Level Measurement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Ultrasonic Level Instrument\ub294\n      \uc218\uc2ed kHz \ub300\uc5ed\uc758 \ucd08\uc74c\ud30c\ub97c \ubc1c\uc0ac\ud558\uace0\n      \uacbd\uacc4\uba74\uc5d0\uc11c \ubc18\uc0ac\ub418\ub294 Echo\ub97c \uac10\uc9c0\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \uc11c\ub85c \ub2e4\ub978 \ub9e4\uc9c8 \uacbd\uacc4\uc5d0\uc11c\n      \uc74c\ud5a5 \ud2b9\uc131\uc774 \uae09\uaca9\ud788 \ubcc0\ud558\uba74 \ubc18\uc0ac\uac00 \ubc1c\uc0dd\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Ultrasonic Pulse\n      \u2192\n      Interface Reflection\n      \u2192\n      Echo Time\n      \u2192\n      Level\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.5 Ullage\uc640 Fillage<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\uad6c\ubd84<\/th>\n          <th>\uce21\uc815 \uae30\uc900<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>Ullage<\/strong><\/td>\n          <td>Tank \uc0c1\ubd80\uc5d0\uc11c \uc561\uba74\uae4c\uc9c0\uc758 \ube48 \uacf5\uac04 \uac70\ub9ac<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Fillage<\/strong><\/td>\n          <td>Tank \ubc14\ub2e5\uc5d0\uc11c \uc561\uba74\uae4c\uc9c0\uc758 \uc2e4\uc81c \uc561\uccb4 \ub192\uc774<\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n    <pre>\n          Tank Top\n      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n        Sensor\n          \u2502\n          \u2502 Ullage\n          \u25bc\n      ~~~~~~~~~~~~~~~  Liquid Surface\n          \u2502\n          \u2502 Fillage\n          \u2502\n      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n        Tank Bottom\n    <\/pre>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.6 Fillage \uc801\uc6a9 \uc870\uac74<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Fillage \ubc29\uc2dd\uc5d0\uc11c\ub294 Sensor\uc758 \uae30\ubc00 \uc720\uc9c0\uac00 \ud544\uc694\ud558\uba70\n      \ubc14\ub2e5\uc5d0 Sludge\uac00 \uc5c6\uc5b4\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \ub610\ud55c Sound Damping\uc774 \uc2ec\ud558\uba74\n      Echo \uc2e0\ud638\uac00 \uc57d\ud574\uc838 \uce21\uc815\uc774 \uc5b4\ub824\uc6cc\uc9c4\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Fillage\n      \u2192\n      \uae30\ubc00 \uc720\uc9c0\n      +\n      Sludge \uc5c6\uc74c\n      +\n      Sound Damping \ucd5c\uc18c\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.7 Ultrasonic Transmitter \uad6c\uc131<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Ultrasonic Instrument\ub294 \ub2e4\uc74c \uae30\ub2a5\uc744\n      \ud558\ub098\uc758 \uc7a5\uce58\uc5d0 \ud1b5\ud569\ud558\ub294 \ud615\ud0dc\ub85c \uac1c\ubc1c\ub41c\ub2e4.\n    <\/p>\n\n    <ul>\n      <li>Transmitter<\/li>\n      <li>Power<\/li>\n      <li>\uc5f0\uc0b0 Processor<\/li>\n      <li>Signal Processing Circuit<\/li>\n      <li>Ultrasonic Transducer<\/li>\n    <\/ul>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.8 \uace0\uccb4 \ubd84\uccb4\uc758 Ultrasonic \uce21\uc815<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Ultrasonic\uc740 \uace0\uccb4 \ubd84\uccb4 Level\uc5d0\ub3c4 \uc801\uc6a9\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <p>\n      \uadf8\ub7ec\ub098 \uace0\uccb4 \ud45c\uba74\uc774 \uc561\uccb4\ucc98\ub7fc \ud3c9\ud3c9\ud558\uc9c0 \uc54a\uc544\n      Echo\uc758 \ubc29\ud5a5\uacfc \ud06c\uae30\uac00 \ub2ec\ub77c\uc9c8 \uc218 \uc788\uc5b4\n      Level \uce21\uc815\uc774 \uc5b4\ub824\uc6cc\uc9c4\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.9 Radar Level Instrument<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Radar Level Instrument\ub294\n      \ucd08\uc74c\ud30c\uc640 \ub3d9\uc77c\ud558\uac8c Time-of-Flight\ub97c \uc774\uc6a9\ud558\uc9c0\ub9cc,\n      \ucd08\uc74c\ud30c \ub300\uc2e0 GHz \ub300\uc5ed\uc758 Microwave\ub97c \uc0ac\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Ultrasonic\n      \u2192\n      kHz\n    <\/div>\n\n    <div class=\"formula\">\n      Radar\n      \u2192\n      GHz\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.10 Non-contact Radar\uc640 GWR<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\uad6c\ubd84<\/th>\n          <th>Non-contact Radar<\/th>\n          <th>Guided-Wave Radar<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>\uc804\ud30c \uacbd\ub85c<\/strong><\/td>\n          <td>\uacf5\uac04\uc73c\ub85c \ubc29\uc0ac<\/td>\n          <td>Probe\ub97c \ub530\ub77c \uc720\ub3c4<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Signal Loss<\/strong><\/td>\n          <td>\ubc1c\uc0dd<\/td>\n          <td>\ub9e4\uc6b0 \uc791\uc74c<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>\uc8fc\uc694 \uc870\uac74<\/strong><\/td>\n          <td>\uae68\ub057\ud558\uace0 \uac74\uc870\ud55c Antenna Window<\/td>\n          <td>Probe \uc0c1\ud0dc<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Interface<\/strong><\/td>\n          <td>&#8211;<\/td>\n          <td>Liquid-Liquid Interface \uce21\uc815\uc5d0 \uc0ac\uc6a9<\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.11 Radar \uc804\ud30c \uc18d\ub3c4<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Radar \uc804\ud30c \uc18d\ub3c4\ub294\n      \ub9e4\uc9c8\uc758 Relative Permittivity\uc5d0 \ub530\ub77c \ubcc0\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      v\n      =\n      c \/ \u221a\u03b5<sub>r<\/sub>\n    <\/div>\n\n    <ul>\n      <li>c : \uad11\uc18d<\/li>\n      <li>\u03b5<sub>r<\/sub> : Relative Permittivity<\/li>\n    <\/ul>\n\n    <div class=\"formula\">\n      Air\n      \u2192\n      \u03b5<sub>r<\/sub> \u2248 1\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.12 Gas Phase\uc758 Permittivity \ubcf4\uc815<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Gas Phase\uc758 \uc555\ub825\uacfc \uc628\ub3c4\uac00 \ubcc0\ud558\uba74\n      Density\uac00 \ub2ec\ub77c\uc9c0\uace0\n      \u03b5<sub>r<\/sub>\ub3c4 \ud568\uaed8 \ubcc0\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      \u03b5<sub>r<\/sub>\n      =\n      1\n      +\n      (\n      \u03b5<sub>ref<\/sub> &#8211; 1\n      )\n      \u00b7\n      (\n      P T<sub>ref<\/sub>\n      \/\n      P<sub>ref<\/sub>T\n      )\n    <\/div>\n\n    <div class=\"formula\">\n      P \u2191\n      \u2192\n      Density \u2191\n      \u2192\n      \u03b5<sub>r<\/sub> \u2191\n    <\/div>\n\n    <div class=\"formula\">\n      T \u2191\n      \u2192\n      Density \u2193\n      \u2192\n      \u03b5<sub>r<\/sub> \u2193\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.13 Impedance\uc640 Reflection<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc11c\ub85c \ub2e4\ub978 \ub9e4\uc9c8\uc758 Impedance \ucc28\uc774\uac00 \uc874\uc7ac\ud558\uba74\n      \uc804\uc790\ud30c \uc77c\ubd80\uac00 \ubc18\uc0ac\ub41c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Z<sub>0<\/sub>\n      =\n      \u221a(\u03bc<sub>0<\/sub>\/\u03b5<sub>0<\/sub>)\n    <\/div>\n\n    <div class=\"formula\">\n      \u0393\n      =\n      (\n      Z<sub>L<\/sub> &#8211; Z<sub>0<\/sub>\n      )\n      \/\n      (\n      Z<sub>L<\/sub> + Z<sub>0<\/sub>\n      )\n    <\/div>\n\n    <p>\n      \uacf5\uae30\uc5d0\uc11c \uc0c1\ub300\uc720\uc804\uc728 \u03b5<sub>r<\/sub>\uc778\n      \ub9e4\uc9c8\ub85c \uc785\uc0ac\ud558\ub294 \uacbd\uc6b0\uc758 Power Reflection\uc740\n      \ub2e4\uc74c\uacfc \uac19\uc774 \uc815\ub9ac\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      R\n      =\n      |\u0393|\u00b2\n      =\n      |\n      (\n      \u221a\u03b5<sub>r<\/sub> &#8211; 1\n      )\n      \/\n      (\n      \u221a\u03b5<sub>r<\/sub> + 1\n      )\n      |\u00b2\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        \u03b5<sub>r<\/sub> \ucc28\uc774\uac00 \uc791\uc73c\uba74 Reflection\uc774 \uc791\uace0,\n        \ud22c\uacfc\ub418\ub294 \uc804\uc790\ud30c\uac00 \ub9ce\uc544\uc9c4\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.14 GWR Interface Measurement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      GWR\uc740 Probe\ub97c \ub530\ub77c Microwave\ub97c \uc804\uc1a1\ud558\uc5ec\n      \uc11c\ub85c \ub2e4\ub978 \uc561\uccb4\uc758 \uacbd\uacc4\uc5d0\uc11c \ubc1c\uc0dd\ud558\ub294\n      Echo \ubcc0\ud654\ub97c \uc774\uc6a9\ud574 Interface\ub97c \uce21\uc815\ud55c\ub2e4.\n    <\/p>\n\n    <pre>\n          GWR Probe\n              \u2502\n              \u2502\n      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u253c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Upper Liquid\n              \u2502\n              \u2502  Microwave \uc77c\ubd80 \ud22c\uacfc\n              \u2502\n      --------\u253c-------- Interface\n              \u2502\n              \u2502\n      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u253c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Lower Liquid \/ Water\n              \u2502\n    <\/pre>\n\n    <p>\n      \uc0c1\ubd80 \uc720\uccb4\ub97c \ud22c\uacfc\ud55c Microwave\uac00\n      \ud558\ubd80\uc758 \ubb3c\uacfc \ub9cc\ub098\uba74\n      \uae09\uaca9\ud55c Energy Loss\uac00 \ubc1c\uc0dd\ud558\uace0,\n      Echo Curve \ubd84\uc11d\uc5d0 \uc774\ub97c \uc774\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.15 Transition Zone<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      GWR Probe\uc758 \uc591 \ub05d\ub2e8 \ubd80\uadfc\uc5d0\ub294\n      \uce21\uc815\uc774 \uc5b4\ub824\uc6b4 Transition Zone\uc774 \uc874\uc7ac\ud55c\ub2e4.\n    <\/p>\n\n    <pre>\n          Top\n           \u2502\n      [ Transition Zone ]\n           \u2502\n           \u2502\n        Measuring\n          Range\n           \u2502\n           \u2502\n      [ Transition Zone ]\n           \u2502\n         Bottom\n    <\/pre>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.16 Laser Level Measurement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Laser Level Instrument\ub294\n      Laser \uad11\uc120\uc744 \ub300\uc0c1 \ud45c\uba74\uc5d0 \uc870\uc0ac\ud558\uace0\n      \ubc18\uc0ac\ub418\uc5b4 \ub3cc\uc544\uc624\ub294 Time-of-Flight\ub97c \uce21\uc815\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Laser\n      \u2192\n      Surface Reflection\n      \u2192\n      ToF\n      \u2192\n      Distance\n      \u2192\n      Level\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c \ub300\uc0c1 \ud45c\uba74\uc5d0\uc11c\n      \ucda9\ubd84\ud55c Laser Reflection\uc774 \ud655\ubcf4\ub418\uc5b4\uc57c \ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.5.17 Magnetostrictive Level Measurement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Magnetostrictive \ubc29\uc2dd\uc740\n      \ub3c4\uc120\uc5d0 \uc778\uac00\ub41c Electric Pulse\uc640\n      Magnetic Float\uc758 \uc790\uae30\uc7a5\uc774 \ub9cc\ub0a0 \ub54c \ubc1c\uc0dd\ud558\ub294\n      Mechanical Torsion Pulse\ub97c \uc774\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n    <pre>\n        Electric Pulse\n              \u2502\n              \u25bc\n          Waveguide\n              \u2502\n              \u2502\n          Magnetic Float\n              \u2502\n              \u25bc\n      Mechanical Torsion Pulse\n              \u2502\n              \u25bc\n        Propagation Time\n              \u2502\n              \u25bc\n           Position\n              \u2502\n              \u25bc\n            Level\n    <\/pre>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.6 Weight<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Weight \ubc29\uc2dd\uc740 Tank \uc9c0\uc9c0\ubd80\uc5d0\n      Load Cell\uc744 \uc124\uce58\ud558\uc5ec\n      \uc804\uccb4 \uc911\ub7c9\uc744 \uce21\uc815\ud558\uace0 Level\ub85c \ud658\uc0b0\ud55c\ub2e4.\n    <\/p>\n\n    <pre>\n             Tank\n        \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\n        \u2502             \u2502\n        \u2502   Material  \u2502\n        \u2502             \u2502\n        \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518\n          \u2502         \u2502\n      Load Cell  Load Cell\n    <\/pre>\n\n    <p>\n      \uc815\ud655\ud55c \uc5f0\uc0b0\uc744 \uc704\ud574\n      Empty Tank Weight\ub97c \uc54c\uace0 \uc788\uc5b4\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Material Weight\n      =\n      Total Weight\n      &#8211;\n      Empty Tank Weight\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.6.1 Weight \ubc29\uc2dd\uc758 \uc801\uc6a9<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Weight \ubc29\uc2dd\uc740 \uc561\uccb4\ubfd0 \uc544\ub2c8\ub77c\n      Solid Powder\uc640 Bulk Storage\uc5d0\ub3c4 \uc801\uc6a9\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <p>\n      Level\ub85c \ud658\uc0b0\ud558\uae30 \uc704\ud574\uc11c\ub294\n      \ub0b4\uc6a9\ubb3c\uc758 Density\uac00 \uc77c\uc815\ud574\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Weight\n      \u2192\n      Density\n      \u2192\n      Volume\n      \u2192\n      Level\n    <\/div>\n\n    <p>\n      \uace0\uccb4\uc758 \uacbd\uc6b0 \uc801\uc7ac \uc0c1\ud0dc\uc5d0 \ub530\ub77c\n      Density\uac00 \ub2ec\ub77c\uc9c8 \uc218 \uc788\uc5b4 \uc624\ucc28\uac00 \ubc1c\uc0dd\ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.6.2 Piezo<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc81c\uacf5 \uc790\ub8cc\uc5d0\uc11c\ub294\n      Piezo \uc18c\uc790\uac00 \uc9c4\ub3d9\uc744 \ub9cc\ub4e4\uc5b4 \ub0b4\ub294 \ub370\n      \uc0ac\uc6a9\ub41c\ub2e4\uace0 \uae30\ub85d\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Piezo\n      \u2192\n      Vibration\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.7 Capacitive Level Measurement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Capacitive Level Instrument\ub294\n      \uc815\uc804\uc6a9\ub7c9 \ubcc0\ud654\ub85c Level\uc744 \uce21\uc815\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      C\n      =\n      \u03b5A\/d\n    <\/div>\n\n    <ul>\n      <li>C : Capacitance<\/li>\n      <li>\u03b5 : Permittivity<\/li>\n      <li>A : Electrode Area<\/li>\n      <li>d : Electrode Distance<\/li>\n    <\/ul>\n\n    <p>\n      A\uc640 d\ub294 \uace0\uc815\ub418\uc5b4 \uc788\uc73c\ubbc0\ub85c\n      Level \ubcc0\ud654\uc5d0 \ub530\ub978 \u03b5 \ubcc0\ud654\uac00\n      \uc2e4\uc9c8\uc801\uc778 \uce21\uc815 \ubcc0\uc218\uac00 \ub41c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Level \ubcc0\ud654\n      \u2192\n      Dielectric Material \ubcc0\ud654\n      \u2192\n      \u03b5 \ubcc0\ud654\n      \u2192\n      C \ubcc0\ud654\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.7.1 Conductive Liquid<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \ub300\uc0c1 \uc561\uccb4\uac00 Conductive\uc778 \uacbd\uc6b0\n      Probe\uac00 \uc9c1\uc811 \uc804\uae30\uc801\uc73c\ub85c \uc811\ucd09\ud558\uc9c0 \uc54a\ub3c4\ub85d\n      \uc808\uc5f0 \uc720\uc804\uccb4\ub85c \ucf54\ud305\ud558\uc5ec \uc0ac\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Conductive Liquid\n      \u2192\n      Insulated Probe\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.8 Radiation Level Measurement<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Radiation \ubc29\uc2dd\uc740\n      X-ray \ub610\ub294 Gamma-ray \ub4f1\uc758 \ubc29\uc0ac\uc120\uc744\n      Tank \uc678\ubd80\uc5d0\uc11c \ud22c\uacfc\uc2dc\ucf1c\n      \uac10\uc1e0 \uc815\ub3c4\ub85c Level\uc744 \uce21\uc815\ud55c\ub2e4.\n    <\/p>\n\n    <pre>\n      Radiation Source\n             \u2502\n             \u2502  X-ray \/ Gamma-ray\n             \u25bc\n      \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\n      \u2502       Tank       \u2502\n      \u2502      Material    \u2502\n      \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518\n             \u2502\n             \u25bc\n         Detector\n    <\/pre>\n\n    <div class=\"formula\">\n      Level \u2191\n      \u2192\n      Radiation Attenuation \u2191\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.8.1 Radiation \ubc29\uc2dd\uc758 \uc801\uc6a9<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Sensor\uac00 Process \ub0b4\ubd80\uc640 \uc9c1\uc811 \uc811\ucd09\ud558\uc9c0 \uc54a\uc73c\ubbc0\ub85c\n      \uace0\uc628, \uace0\uc555, \uac15\ubd80\uc2dd\uc131 \ub4f1\uc758\n      \uac00\ud639\ud55c \ud658\uacbd\uc5d0 \uc801\uc6a9\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Non-contact\n      \u2192\n      High Temperature\n      +\n      High Pressure\n      +\n      Corrosive Process\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.8.2 Radiation Safety<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Radiation Source\ub294 \ud56d\uc0c1 \ubc29\uc0ac\uc120\uc744 \ubc29\ucd9c\ud558\ub294\n      Always-on \ubc29\uc2dd\uc774\ubbc0\ub85c\n      \uc791\uc5c5\uc790 \ubcf4\ud638\ub97c \uc704\ud55c \ucc28\ud3d0\uac00 \ud544\uc694\ud558\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      Radiation Source\n      \u2192\n      Always On\n      \u2192\n      Pb Shielding\n    <\/div>\n\n    <div class=\"warning\">\n      <strong>\n        Radiation Level Instrument\ub294\n        \uc791\uc5c5\uc790 \uc548\uc804\uc744 \uc704\ud574 \ub0a9(Pb) \ucc28\ud3d0 \uad6c\uc870\ub97c \uc801\uc6a9\ud55c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.9 Level Sensor Accessory \u2014 Stilling Well<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Stilling Well\uc740\n      \uae09\uaca9\ud55c \uc720\uccb4 \ud750\ub984, \uc9c4\ub3d9, \uc694\ub3d9, \ud30c\ub3c4 \ub4f1\uc73c\ub85c\ubd80\ud130\n      Level Sensor\ub97c \ubcf4\ud638\ud558\uace0\n      \uc548\uc815\uc801\uc778 \uc561\uc704\ub97c \uc81c\uacf5\ud558\ub294 \ubcf4\ud638 Pipe\uc774\ub2e4.\n    <\/p>\n\n    <pre>\n        Tank\n      \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\n      \u2502   ~ ~ ~ ~ ~ ~      \u2502\n      \u2502      \u2502              \u2502\n      \u2502      \u2502 Stilling     \u2502\n      \u2502      \u2502 Well         \u2502\n      \u2502      \u2502              \u2502\n      \u2502      \u2502 Sensor       \u2502\n      \u2502      \u2502              \u2502\n      \u2502   ~ ~\u2502~ ~ ~ ~      \u2502\n      \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2534\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518\n    <\/pre>\n\n    <div class=\"formula\">\n      Flow \/ Wave \/ Vibration\n      \u2192\n      Stilling Well\n      \u2192\n      Stable Level\n      \u2192\n      Measurement Error \uac10\uc18c\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.9.1 Stilling Well \uc124\uce58 \uc870\uac74<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Tank \ub0b4\ubd80\uc758 \uc2e4\uc81c Level\uacfc\n      Stilling Well \ub0b4\ubd80 Level\uc774 \ub3d9\uc77c\ud558\uac8c \uc6c0\uc9c1\uc774\ub3c4\ub85d\n      \uc720\uccb4\uac00 \uc790\uc720\ub86d\uac8c \ucd9c\uc785\ud560 \uc218 \uc788\uc5b4\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \uc81c\uacf5 \uc790\ub8cc\uc5d0\uc11c\ub294\n      Stilling Well\uc758 \uc704\u00b7\uc544\ub798\uac00 \ud56d\uc0c1\n      \uc720\uccb4\uc640 \uc5f0\uacb0\ub418\ub3c4\ub85d \uc124\uce58\ud558\ub294 \uac83\uc774 \uc911\uc694\ud558\ub2e4\uace0 \uae30\ub85d\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        Stilling Well \ub0b4\ubd80 Level\uc774\n        Tank Level\uacfc \ud56d\uc0c1 \uc5f0\ub3d9\ub418\ub3c4\ub85d\n        \uc704\u00b7\uc544\ub798 \uc720\uccb4 \ud1b5\ub85c\ub97c \ud655\ubcf4\ud55c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.10 Level Measurement \uc804\uccb4 \ube44\uad50<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\ubc29\uc2dd<\/th>\n          <th>\uce21\uc815 \uc6d0\ub9ac<\/th>\n          <th>\ud575\uc2ec \uc601\ud5a5 \ubcc0\uc218<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>Displacer<\/strong><\/td>\n          <td>Buoyant Force<\/td>\n          <td>Density<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Ultrasonic<\/strong><\/td>\n          <td>Sound ToF<\/td>\n          <td>Sound Speed<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Radar<\/strong><\/td>\n          <td>Microwave ToF<\/td>\n          <td>Permittivity<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>GWR<\/strong><\/td>\n          <td>Probe Guided Microwave<\/td>\n          <td>Permittivity \/ Interface<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Laser<\/strong><\/td>\n          <td>Laser ToF<\/td>\n          <td>Surface Reflection<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Magnetostrictive<\/strong><\/td>\n          <td>Mechanical Pulse Time<\/td>\n          <td>Float Position<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Weight<\/strong><\/td>\n          <td>Load Cell<\/td>\n          <td>Density \/ Empty Tank Weight<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Capacitive<\/strong><\/td>\n          <td>Capacitance<\/td>\n          <td>Permittivity<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Radiation<\/strong><\/td>\n          <td>Radiation Attenuation<\/td>\n          <td>Material Thickness<\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.11 Chapter 20 \uc804\uccb4 \ud750\ub984<\/h2>\n\n  <div class=\"card\">\n\n    <pre>\n                      Level Measurement\n                             \u2502\n          \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u253c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\n          \u25bc                  \u25bc                  \u25bc\n      Force \uae30\ubc18          Echo \uae30\ubc18         \ubb3c\uc131 \uae30\ubc18\n          \u2502                  \u2502                  \u2502\n          \u25bc                  \u25bc                  \u25bc\n     Displacer         Ultrasonic           Capacitive\n       Weight             Radar             Radiation\n                         Laser\n                    Magnetostrictive\n                             \u2502\n                             \u25bc\n                      Sensor Accessory\n                             \u2502\n                             \u25bc\n                       Stilling Well\n    <\/pre>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>20.12 \ud575\uc2ec \uc554\uae30 \uc815\ub9ac<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\ud56d\ubaa9<\/th>\n          <th>\ud575\uc2ec<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>Displacer<\/strong><\/td>\n          <td>F<sub>B<\/sub>=\u03b3V=\u03c1gV, Density\uac00 \ud575\uc2ec<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Interface Displacer<\/strong><\/td>\n          <td>F<sub>B<\/sub>=\u03b3\u2081V\u2081+\u03b3\u2082V\u2082<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Echo<\/strong><\/td>\n          <td>Time-of-Flight, Speed\uac00 \ud575\uc2ec<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Echo \uacf5\ud1b5 \ubb38\uc81c<\/strong><\/td>\n          <td>Foam, \ubd88\uba85\ud655\ud55c Interface, \uc7a5\uc560\ubb3c, Dead Zone<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Ultrasonic<\/strong><\/td>\n          <td>\uc218\uc2ed kHz, Sound Speed \uc601\ud5a5<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Radar<\/strong><\/td>\n          <td>GHz Microwave, v=c\/\u221a\u03b5<sub>r<\/sub><\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>GWR<\/strong><\/td>\n          <td>Probe Guided Wave, Interface \uce21\uc815<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Reflection<\/strong><\/td>\n          <td>Permittivity \ucc28\uc774\ub85c Echo \ubc1c\uc0dd<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Weight<\/strong><\/td>\n          <td>Load Cell, Empty Tank Weight \ud544\uc694<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Capacitive<\/strong><\/td>\n          <td>C=\u03b5A\/d<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Radiation<\/strong><\/td>\n          <td>\ube44\uc811\ucd09, \uadf9\ud55c \ud658\uacbd, Pb Shielding<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Stilling Well<\/strong><\/td>\n          <td>Flow\u00b7Wave\u00b7Vibration \uc5b5\uc81c, Tank Level\uacfc \uc5f0\ub3d9<\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <div class=\"warning\">\n\n    <strong>\n      \uc774 HTML\uc740 \uc0ac\uc6a9\uc790\uac00 \uc81c\uacf5\ud55c\n      Chapter 20 Level Measurement \uc815\ub9ac \ub0b4\uc6a9\ub9cc\uc744\n      \uc7ac\uad6c\uc131\ud558\uc5ec \uc791\uc131\ud558\uc600\ub2e4.\n\n      Displacement\uc758 \ubd80\ub825,\n      Wet\/Dry Calibration,\n      Torque Tube,\n      Liquid-Liquid Interface,\n      Echo \ubc29\uc2dd\uc758 Speed\uc640 \uacf5\ud1b5 \uc81c\uc57d,\n      Ultrasonic,\n      Radar \ubc0f Guided-Wave Radar,\n      Permittivity\uc640 Reflection,\n      Laser,\n      Magnetostrictive,\n      Weight,\n      Capacitive,\n      Radiation,\n      Stilling Well \uc21c\uc11c\ub85c \uad6c\uc131\ud558\uc600\ub2e4.\n\n      \uc81c\uacf5\ub41c \ub0b4\uc6a9\uc5d0 \uc5c6\ub294 \ucd94\uac00 \uacc4\uce21 \ubc29\uc2dd,\n      \uc81c\uc870\uc0ac\ubcc4 \ud2b9\uc131,\n      \ucd94\uac00 \ubcf4\uc815\uc2dd,\n      \uc124\uce58 \uaddc\uaca9,\n      \uc678\ubd80 \ud45c\uc900 \ub0b4\uc6a9\uc740 \ubcc4\ub3c4\ub85c \ucd94\uac00\ud558\uc9c0 \uc54a\uc558\ub2e4.\n    <\/strong>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <div class=\"keywords\">\n    Level Measurement,\n    Displacement,\n    Displacer,\n    Buoyancy,\n    Buoyant Force,\n    Density,\n    Torque Tube,\n    Magnetic Coupling,\n    Bellows,\n    Interface Level,\n    Echo,\n    Time of Flight,\n    Ultrasonic,\n    Ullage,\n    Fillage,\n    Radar,\n    Microwave,\n    Guided Wave Radar,\n    GWR,\n    Permittivity,\n    Reflection Coefficient,\n    Transition Zone,\n    Laser,\n    Magnetostrictive,\n    Load Cell,\n    Weight,\n    Capacitive Level,\n    Radiation Level,\n    Stilling Well\n  <\/div>\n\n<\/div>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/10\/Lessons_In_Industrial_Instrumentation-4.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Lessons_In_Industrial_Instrumentation-4\uc758 \uc0bd\uc785.\"><\/object><a id=\"wp-block-file--media-5e787aa4-5174-440d-9b4a-5eb5c47c79c7\" href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/10\/Lessons_In_Industrial_Instrumentation-4.pdf\">Lessons_In_Industrial_Instrumentation-4<\/a><a href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/10\/Lessons_In_Industrial_Instrumentation-4.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-5e787aa4-5174-440d-9b4a-5eb5c47c79c7\">\ub2e4\uc6b4\ub85c\ub4dc<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Chapter 20. Level Measurement Displacement \u00b7 Echo \u00b7 Ultrasonic \u00b7 Radar \u00b7 GWR \u00b7 Laser \u00b7 Magnetostrictive \u00b7 Weight \u00b7 Capacitive \u00b7 Radiation \u00b7 Stilling Well 20.4 Displacement Displacement \ubc29\uc2dd\uc740 \uc720\uccb4\uac00 \ubb3c\uccb4\uc5d0 \uac00\ud558\ub294 \ubd80\ub825(Buoyant Force)\uc744 \uc774\uc6a9\ud558\uc5ec Level\uc744 \uce21\uc815\ud55c\ub2e4. \uc561\uc704\uac00 \uc99d\uac00\ud560\uc218\ub85d Displacer\uac00 \uc720\uccb4\uc5d0 \ub354 \ub9ce\uc774 \uc7a0\uae30\uace0, \ubb3c\uccb4\uc5d0 \uc791\uc6a9\ud558\ub294 \ubd80\ub825\uc774 \uc99d\uac00\ud55c\ub2e4. \ub530\ub77c\uc11c \uc13c\uc11c\uac00 \uac10\uc9c0\ud558\ub294 \ubb3c\uccb4\uc758 \uac89\ubcf4\uae30 \ubb34\uac8c\ub294 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1185],"tags":[2205,2202,2203,2208,2204,2199,2200,2211,2217,2222,1529,2194,2218,2201,2210,2207,2209,2219,2223,2011,2216,2221,2214,2206,2220,2215,2213,2212],"class_list":["post-9745","post","type-post","status-publish","format-standard","hentry","category-1185","tag-bellows","tag-buoyancy","tag-buoyant-force","tag-capacitive-level","tag-density","tag-displacement","tag-displacer","tag-echo","tag-fillage","tag-guided-wave-radar","tag-gwr","tag-interface-level","tag-laser","tag-level-measurement-2","tag-load-cell","tag-magnetic-coupling","tag-magnetostrictive","tag-microwave","tag-permittivity","tag-radar","tag-radiation-level","tag-reflection-coefficient","tag-time-of-flight","tag-torque-tube","tag-transition-zone","tag-ullage","tag-ultrasonic","tag-weight"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9745","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/comments?post=9745"}],"version-history":[{"count":2,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9745\/revisions"}],"predecessor-version":[{"id":9751,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9745\/revisions\/9751"}],"wp:attachment":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/media?parent=9745"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/categories?post=9745"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/tags?post=9745"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}