{"id":9529,"date":"2026-09-30T22:26:46","date_gmt":"2026-09-30T13:26:46","guid":{"rendered":"https:\/\/now0930.pe.kr\/wordpress\/?p=9529"},"modified":"2026-09-30T22:27:28","modified_gmt":"2026-09-30T13:27:28","slug":"chapter-20","status":"publish","type":"post","link":"https:\/\/now0930.pe.kr\/wordpress\/chapter-20\/","title":{"rendered":"Lessons In Industrial Instrumentation, Chapter 20"},"content":{"rendered":"\n<div class=\"chapter19-wide\">\n\n  <h1>Chapter 20. Continuous Level Measurement<\/h1>\n\n  <div class=\"subtitle\">\n    \uc6a9\uc5b4 \uc815\uc758 \u2192 \uc6a9\uc5b4 \uac04 \uad00\uacc4 \u2192 \uc2a4\ud1a0\ub9ac \u2192 \ud604\uc7a5 \uc801\uc6a9\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>1. Chapter 20 \uc804\uccb4 \ud750\ub984<\/h2>\n\n  <div class=\"card\">\n\n    <div class=\"memory\">\n      <strong>\n        \uc6a9\uae30 \uc548\uc5d0 \ub4e4\uc5b4 \uc788\ub294 \uc720\uccb4\uc758 \ub192\uc774\ub97c\n        \uc5b4\ub5bb\uac8c \uce21\uc815\ud560 \uac83\uc778\uac00?\n      <\/strong>\n    <\/div>\n\n    <div class=\"flow\">\n      \uc9c1\uc811 \uad00\ucc30\n      \u2192 \uc704\uce58 \uce21\uc815\n      \u2192 \uc815\uc218\uc555 \uce21\uc815\n      \u2192 \ubcf4\uc0c1\n      \u2192 \ubc00\ub3c4 \uacc4\uc0b0\n      \u2192 Interface \uce21\uc815\n    <\/div>\n\n    <p>\n      Level measurement\ub294 \uc561\uccb4\uc758 \ub192\uc774\ub97c \uc9c1\uc811 \ubcf4\ub294 \uac83\uc5d0\uc11c \uc2dc\uc791\ud55c\ub2e4.\n      \uac00\uc7a5 \ub2e8\uc21c\ud55c \ubc29\ubc95\uc740 Sight Glass\uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \ub2e4\uc74c\uc73c\ub85c Float\ub97c \uc774\uc6a9\ud558\uc5ec \uc561\uba74\uc758 \uc704\uce58\ub97c \uac80\ucd9c\ud558\uace0,\n      \uc561\uccb4\uc758 \ub192\uc774\uac00 \ub9cc\ub4dc\ub294 \uc815\uc218\uc555\uc744 \uc774\uc6a9\ud558\uc5ec\n      pressure transmitter\ub85c level\uc744 \uce21\uc815\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P = \u03c1gh\n    <\/div>\n\n    <p>\n      \uc2e4\uc81c \uacf5\uc815\uc5d0\uc11c\ub294 gas pressure, transmitter \uc124\uce58 \ub192\uc774,\n      wet leg, density \ubcc0\ud654, liquid-liquid interface \ub4f1\uc758\n      \uc601\ud5a5\ub3c4 \ud568\uaed8 \uace0\ub824\ud574\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"sequence\">\n      Sight Glass\n      \u2192 Float\n      \u2192 Hydrostatic Pressure\n      \u2192 DP Compensation\n      \u2192 Density Compensation\n      \u2192 Interface Measurement\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>2. \uc6a9\uc5b4 \uc815\uc758<\/h2>\n\n\n  <!-- ================================================= -->\n  <h3>2.1 Sight Glass \/ Level Gauge<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      Sight Glass\ub294 vessel \ub0b4\ubd80\uc758 \uc561\uba74\uc744\n      \uc678\ubd80\uc5d0\uc11c \uc9c1\uc811 \ubcfc \uc218 \uc788\ub3c4\ub85d \ub9cc\ub4e0\n      \uac00\uc7a5 \ub2e8\uc21c\ud55c level measurement \uc7a5\uce58\uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \uae30\ubcf8 \uc6d0\ub9ac\ub294 \uc5f0\uacb0\ub41c \uc720\uccb4\uc758 \uc555\ub825 \ud3c9\ud615\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        Vessel \ub0b4\ubd80\uc758 \uc720\uccb4 \uad6c\uc870\n        \u2248\n        Sight Glass \ub0b4\ubd80\uc758 \uc720\uccb4 \uad6c\uc870\n      <\/strong>\n    <\/div>\n\n\n    <h4>\ub2e8\uc77c \uc561\uccb4\uc758 \uacbd\uc6b0<\/h4>\n\n    <p>\n      Vessel\uc5d0 \ubb3c\uacfc \uacf5\uae30\uac00 \uc788\ub2e4\uace0 \ud558\uc790.\n    <\/p>\n\n    <div class=\"grid-2\">\n\n      <div class=\"memory\">\n        <strong>\uc704\ucabd \uc720\uccb4<\/strong>\n        <br><br>\n        Air\n      <\/div>\n\n      <div class=\"memory\">\n        <strong>\uc544\ub798\ucabd \uc720\uccb4<\/strong>\n        <br><br>\n        Water\n      <\/div>\n\n    <\/div>\n\n    <p>\n      Sight Glass\ub3c4 \uc704\ucabd\uc740 air,\n      \uc544\ub798\ucabd\uc740 water\uc640 \uc5f0\uacb0\ub418\uc5b4\uc57c\n      vessel\uacfc \ub3d9\uc77c\ud55c \uc561\uba74\uc744 \ub098\ud0c0\ub0b8\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Upper Connection = Air\n      <br><br>\n      Lower Connection = Water\n    <\/div>\n\n\n    <h4>Liquid-Liquid Interface<\/h4>\n\n    <p>\n      Oil\uacfc Water\ucc98\ub7fc \uc11c\ub85c \uc11e\uc774\uc9c0 \uc54a\ub294 \ub450 \uc561\uccb4\uac00 \uc788\ub2e4\uba74\n      \uad00\uc2ec \ub300\uc0c1\uc740 \uc804\uccb4 \uc561\uba74\uc774 \uc544\ub2c8\ub77c \ub450 \uc561\uccb4\uc758 \uacbd\uacc4\uba74\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Light Liquid\n      <br>\u2193<br>\n      Interface\n      <br>\u2193<br>\n      Heavy Liquid\n    <\/div>\n\n    <p>\n      Sight Glass\uc5d0\ub3c4 \uac19\uc740 \ub450 \uc561\uccb4\uc758 \uad6c\uc870\uac00 \ud615\uc131\ub418\uc5b4\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        Upper Nozzle = Light Liquid\n        <br><br>\n        Lower Nozzle = Heavy Liquid\n      <\/strong>\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c \ub2e8\uc77c \uc561\uccb4 level\uacfc liquid-liquid interface\ub294\n      \ubcf8\uc9c8\uc801\uc73c\ub85c \uac19\uc740 \uc6d0\ub9ac\uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \uce21\uc815\ud558\ub824\ub294 \uacbd\uacc4\uba74\uc758 \uc704\ucabd \uc720\uccb4\uc640 \uc544\ub798\ucabd \uc720\uccb4\ub97c\n      Sight Glass\uc5d0\ub3c4 \ub3d9\uc77c\ud558\uac8c \uc5f0\uacb0\ud574\uc57c \ud55c\ub2e4.\n    <\/p>\n\n\n    <h4>Sight Glass\uc758 \ud604\uc7a5 \ubb38\uc81c<\/h4>\n\n    <ul>\n      <li>\ub0b4\ubd80 \uc624\uc5fc \uc2dc \uc721\uc548 \ud310\ub3c5\uc774 \uc5b4\ub824\uc6cc\uc9c4\ub2e4.<\/li>\n      <li>\ud56d\uc0c1 \uae68\ub057\ud55c \uc0c1\ud0dc\ub97c \uc720\uc9c0\ud574\uc57c \ud55c\ub2e4.<\/li>\n      <li>Glass tube\ub294 thermal shock \ub610\ub294 mechanical shock\uc5d0 \uc758\ud574 rupture\ub420 \uc218 \uc788\ub2e4.<\/li>\n      <li>\uace0\uc628\u00b7\uace0\uc555 \uacf5\uc815\uc5d0\uc11c\ub294 \uc7ac\uc9c8\uacfc \uad6c\uc870\uc5d0 \uc8fc\uc758\ud574\uc57c \ud55c\ub2e4.<\/li>\n      <li>Interface \uce21\uc815\uc5d0\uc11c\ub294 nozzle \uc704\uce58\uac00 \uc798\ubabb\ub418\uba74 \uc624\ucc28\uac00 \ubc1c\uc0dd\ud55c\ub2e4.<\/li>\n    <\/ul>\n\n    <p>\n      Magnetic level gauge\uc5d0\uc11c\ub294 magnetic float\uc640\n      High \/ Low magnetic switch\ub97c \ucd94\uac00\ud558\uc5ec\n      remote indication \ub610\ub294 alarm \uae30\ub2a5\uc744 \uad6c\uc131\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h3>2.2 Float Level Measurement<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      Float \ubc29\uc2dd\uc740 \uc561\uba74 \uc704\uc5d0 \ub728\ub294 \ubb3c\uccb4\uc758 \uc704\uce58\ub97c \uc774\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Liquid Level\n      \u2192 Float Position\n    <\/div>\n\n    <p>\n      \uc561\uba74\uc774 \uc62c\ub77c\uac00\uba74 float\ub3c4 \uc62c\ub77c\uac00\uace0,\n      \uc561\uba74\uc774 \ub0b4\ub824\uac00\uba74 float\ub3c4 \ub0b4\ub824\uac04\ub2e4.\n    <\/p>\n\n\n    <h4>Guide Wire<\/h4>\n\n    <p>\n      Tank \ub0b4\ubd80\uc5d0 turbulence\uac00 \uc788\uc73c\uba74\n      float\uac00 \uc88c\uc6b0\ub85c \ud754\ub4e4\ub9b4 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <p>\n      Guide wire\ub294 float\uc758 \uc6c0\uc9c1\uc784\uc744\n      \uc218\uc9c1 \ubc29\ud5a5\uc73c\ub85c \uc81c\ud55c\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Turbulence\n      \u2192 Float \ud754\ub4e4\ub9bc\n      \u2192 Guide Wire\n      \u2192 \uc218\uc9c1 \uc774\ub3d9 \uc720\uc9c0\n    <\/div>\n\n\n    <h4>Tape \ubc29\uc2dd<\/h4>\n\n    <p>\n      Float \uc704\uce58\ub97c tape \ub610\ub294 mechanical linkage\ub97c \uc774\uc6a9\ud558\uc5ec\n      \uc678\ubd80 indicator\ub85c \uc804\ub2ec\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <p>\n      \uadf8\ub7ec\ub098 \ub2e4\uc74c\uacfc \uac19\uc740 \ubb38\uc81c\uac00 \ubc1c\uc0dd\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <ul>\n      <li>Friction<\/li>\n      <li>Tape \ub298\uc5b4\ub0a8<\/li>\n      <li>Mechanical wear<\/li>\n      <li>Sticking<\/li>\n    <\/ul>\n\n\n    <h4>Ultrasonic\uacfc\uc758 \uad6c\ubd84<\/h4>\n\n    <div class=\"grid-2\">\n\n      <div class=\"memory\">\n        <strong>Float<\/strong>\n        <br><br>\n        \uc561\uba74\uc744 \ub530\ub77c \uc6c0\uc9c1\uc774\ub294 \ubb3c\uccb4\uc758 \uc704\uce58 \uce21\uc815\n      <\/div>\n\n      <div class=\"memory\">\n        <strong>Ultrasonic<\/strong>\n        <br><br>\n        \uc74c\ud30c \uc655\ubcf5\uc2dc\uac04\uc744 \uc774\uc6a9\ud55c \uac70\ub9ac \uce21\uc815\n      <\/div>\n\n    <\/div>\n\n    <p>\n      \ub450 \ubc29\uc2dd \ubaa8\ub450 level\uc744 \uce21\uc815\ud558\uc9c0\ub9cc\n      \uce21\uc815 \uc6d0\ub9ac\ub294 \uc11c\ub85c \ub2e4\ub974\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h3>2.3 Hydrostatic Pressure<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      \uc815\uc9c0\ud55c \uc561\uccb4\ub294 \uc790\uc2e0\uc758 \ubb34\uac8c \ub54c\ubb38\uc5d0 \uc555\ub825\uc744 \ub9cc\ub4e0\ub2e4.\n      \uc774\ub97c \uc815\uc218\uc555\uc774\ub77c\uace0 \ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P = \u03c1gh\n    <\/div>\n\n    <p>\n      Specific weight\ub97c \uc0ac\uc6a9\ud558\uba74 \ub2e4\uc74c\uacfc \uac19\uc774 \ub098\ud0c0\ub0bc \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P = \u03b3h\n    <\/div>\n\n    <div class=\"formula\">\n      \u03b3 = \u03c1g\n    <\/div>\n\n\n    <div class=\"table-wrap\">\n\n      <table>\n\n        <thead>\n          <tr>\n            <th>\uae30\ud638<\/th>\n            <th>\uc758\ubbf8<\/th>\n          <\/tr>\n        <\/thead>\n\n        <tbody>\n          <tr>\n            <td>P<\/td>\n            <td>Hydrostatic Pressure<\/td>\n          <\/tr>\n\n          <tr>\n            <td>\u03c1<\/td>\n            <td>Liquid Density<\/td>\n          <\/tr>\n\n          <tr>\n            <td>g<\/td>\n            <td>Gravitational Acceleration<\/td>\n          <\/tr>\n\n          <tr>\n            <td>h<\/td>\n            <td>Liquid Height<\/td>\n          <\/tr>\n\n          <tr>\n            <td>\u03b3<\/td>\n            <td>Specific Weight<\/td>\n          <\/tr>\n        <\/tbody>\n\n      <\/table>\n\n    <\/div>\n\n\n    <div class=\"memory\">\n      <strong>\n        \uc815\uc218\uc555\uc740 \uc6a9\uae30\uc758 \ubaa8\uc591\ubcf4\ub2e4\n        \uc561\uccb4\uc758 \ubc00\ub3c4\uc640 \uc218\uc9c1 \ub192\uc774\uc5d0 \uc758\ud574 \uacb0\uc815\ub41c\ub2e4.\n      <\/strong>\n    <\/div>\n\n    <div class=\"formula\">\n      P \u221d \u03c1h\n    <\/div>\n\n    <p>\n      \uac19\uc740 \uc561\uccb4\ub77c\uba74 density\uac00 \uac70\uc758 \uc77c\uc815\ud558\ubbc0\ub85c\n    <\/p>\n\n    <div class=\"formula\">\n      P \u221d h\n    <\/div>\n\n    <p>\n      \uad00\uacc4\ub97c \uc774\uc6a9\ud574 bottom pressure\ub85c\ubd80\ud130 level\uc744 \uacc4\uc0b0\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h3>2.4 Bubbler System<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      Bubbler\ub294 purge gas\ub97c dip tube\ub97c \ud1b5\ud574\n      \uc561\uccb4 \uc18d\uc73c\ub85c \ucc9c\ucc9c\ud788 \uacf5\uae09\ud558\uace0,\n      tube \ub0b4\ubd80\uc5d0 \ud615\uc131\ub418\ub294 back pressure\ub97c \uce21\uc815\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"warning\">\n      <strong>\n        Bubbler\ub294 bubble\uc758 \uac1c\uc218\ub97c \uce21\uc815\ud558\ub294 \uc7a5\uce58\uac00 \uc544\ub2c8\ub2e4.\n      <\/strong>\n\n      <br><br>\n\n      \ub0ae\uc740 \uc720\ub7c9\uc73c\ub85c bubble\uc774 \uacc4\uc18d \ubc1c\uc0dd\ud558\ub3c4\ub85d \ub9cc\ub4e0 \ub4a4\n      \uadf8\ub54c \ud615\uc131\ub418\ub294 gas back pressure\ub97c \uce21\uc815\ud55c\ub2e4.\n    <\/div>\n\n    <p>\n      Dip tube \ub05d\uc758 \uae4a\uc774\uac00 h\uc774\uba74\n      \uadf8 \uc704\uce58\uc5d0\uc11c\uc758 hydrostatic pressure\ub294 \ub2e4\uc74c\uacfc \uac19\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P = \u03c1gh\n    <\/div>\n\n    <p>\n      Bubble\uc774 tube \ub05d\uc5d0\uc11c \ube60\uc838\ub098\uac00\ub824\uba74\n      gas pressure\uac00 liquid pressure\ubcf4\ub2e4 \uc57d\uac04 \ucee4\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      Purge gas flow\uac00 \ucda9\ubd84\ud788 \uc791\ub2e4\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>tube<\/sub> \u2248 \u03c1gh\n    <\/div>\n\n    <p>\n      \ub85c \ubcfc \uc218 \uc788\ub2e4.\n    <\/p>\n\n\n    <h4>Bubbler\uc758 \ub3d9\uc791 \ud750\ub984<\/h4>\n\n    <div class=\"flow\">\n      Purge Gas Supply\n      \u2192 Pressure Regulator\n      \u2192 Flow Restriction\n      \u2192 Dip Tube\n      \u2192 Bubble\n    <\/div>\n\n    <div class=\"flow\">\n      Back Pressure\n      \u2192 Hydrostatic Pressure\n      \u2192 Level\n    <\/div>\n\n\n    <h4>Sight Feed Bubbler\uc640 Rotameter<\/h4>\n\n    <p>\n      Tank \ub0b4\ubd80 dip tube \ub05d\uc758 bubble\uc740\n      \uc6b4\uc804\uc790\uac00 \uc9c1\uc811 \ubcf4\uae30 \uc5b4\ub835\ub2e4.\n    <\/p>\n\n    <p>\n      \uadf8\ub798\uc11c purge gas\uac00 \uc2e4\uc81c\ub85c \ud750\ub974\uace0 \uc788\ub294\uc9c0\ub97c\n      \ubcc4\ub3c4\uc758 \uc7a5\uce58\ub85c \ud655\uc778\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"table-wrap\">\n\n      <table>\n\n        <thead>\n          <tr>\n            <th>\uc7a5\uce58 \/ \uc704\uce58<\/th>\n            <th>\uc5ed\ud560<\/th>\n          <\/tr>\n        <\/thead>\n\n        <tbody>\n\n          <tr>\n            <td>Sight Feed Bubbler<\/td>\n            <td>Purge gas\uac00 \ud750\ub974\ub294\uc9c0 bubble\ub85c \uc9c1\uc811 \ud655\uc778<\/td>\n          <\/tr>\n\n          <tr>\n            <td>Rotameter<\/td>\n            <td>Purge gas flow rate \ud655\uc778<\/td>\n          <\/tr>\n\n          <tr>\n            <td>Dip Tube End<\/td>\n            <td>Purge gas\uac00 process liquid\ub85c \uc2e4\uc81c \ubc30\ucd9c<\/td>\n          <\/tr>\n\n          <tr>\n            <td>Pressure Transmitter<\/td>\n            <td>Back pressure \uce21\uc815<\/td>\n          <\/tr>\n\n        <\/tbody>\n\n      <\/table>\n\n    <\/div>\n\n\n    <h4>Purge Flow\uac00 \ub108\ubb34 \ud06c\uba74 \uc548 \ub418\ub294 \uc774\uc720<\/h4>\n\n    <p>\n      Gas flow\uac00 \ub108\ubb34 \ucee4\uc9c0\uba74\n      tube \ub0b4\ubd80\uc5d0 friction pressure\uac00 \ucd94\uac00\ub41c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>measured<\/sub>\n      =\n      \u03c1gh\n      +\n      P<sub>friction<\/sub>\n    <\/div>\n\n    <p>\n      \uc774 \uacbd\uc6b0 transmitter\ub294 \uc2e4\uc81c\ubcf4\ub2e4 \ub192\uc740 pressure\ub97c \uce21\uc815\ud558\uace0,\n      level\ub3c4 \uc2e4\uc81c\ubcf4\ub2e4 \ub192\uac8c \ud45c\uc2dc\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        Bubbler\uc758 \ud575\uc2ec\uc740 \ub9ce\uc740 purge gas\uac00 \uc544\ub2c8\ub77c\n        \uc791\uace0 \uc548\uc815\uc801\uc778 purge flow\uc774\ub2e4.\n      <\/strong>\n    <\/div>\n\n\n    <h4>Bubbler\uc758 \uc7a5\uc810<\/h4>\n\n    <p>\n      Pressure sensor\uac00 process liquid\uc640 \uc9c1\uc811 \uc811\ucd09\ud560 \ud544\uc694\uac00 \uc5c6\ub2e4.\n    <\/p>\n\n    <ul>\n      <li>Highly corrosive liquid<\/li>\n      <li>Sample port\uac00 \ub9c9\ud788\uae30 \uc26c\uc6b4 liquid<\/li>\n      <li>Pressure sensor\uc640 \uc9c1\uc811 \uc811\ucd09\uc2dc\ud0a4\uae30 \uace4\ub780\ud55c liquid<\/li>\n    <\/ul>\n\n    <p>\n      Pressure sensor diaphragm\uc740 flexible\ud574\uc57c \ud558\ubbc0\ub85c\n      \uc0ac\uc6a9\ud560 \uc218 \uc788\ub294 \uc7ac\ub8cc\uac00 \uc81c\ud55c\ub420 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <p>\n      \ubc18\uba74 dip tube\ub294 \uc6c0\uc9c1\uc77c \ud544\uc694\uac00 \uc5c6\uae30 \ub54c\ubb38\uc5d0\n      process liquid\uc5d0 \uacac\ub51c \uc218 \uc788\ub294 \ub2e4\uc591\ud55c \uc7ac\ub8cc\ub97c \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h3>2.5 Transmitter Suppression and Elevation<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      Pressure transmitter\uc758 \uc124\uce58 \uc704\uce58\uac00\n      process connection\uacfc \ub2e4\ub974\uba74\n      transmitter\uac00 \ubcf4\ub294 pressure\uc5d0 offset\uc774 \ubc1c\uc0dd\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        Level 0%\n        \u2260\n        Transmitter Pressure 0\n      <\/strong>\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c \uc2e4\uc81c \uc124\uce58\uc870\uac74\uc5d0 \ub9de\uac8c\n      LRV\uc640 URV\ub97c \uc124\uc815\ud574\uc57c \ud55c\ub2e4.\n    <\/p>\n\n    <ul>\n      <li><strong>LRV:<\/strong> Lower Range Value<\/li>\n      <li><strong>URV:<\/strong> Upper Range Value<\/li>\n    <\/ul>\n\n    <p>\n      \uc608\ub97c \ub4e4\uc5b4 transmitter\uac00 process connection\ubcf4\ub2e4 \uc704\uc5d0 \uc788\uace0\n      capillary \uc548\uc5d0 fill fluid\uac00 \uc874\uc7ac\ud558\uba74,\n      fill fluid column \ub54c\ubb38\uc5d0 0%\uc5d0\uc11c\ub3c4\n      negative pressure\uac00 \ubc1c\uc0dd\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      \uc124\uce58 \ub192\uc774 \ucc28\uc774\n      \u2192 Hydrostatic Offset\n      \u2192 LRV \/ URV \ubcf4\uc815\n    <\/div>\n\n    <p>\n      \uc989 suppression \/ elevation\uc758 \ud575\uc2ec\uc740\n      \uc124\uce58 \ub192\uc774\uc5d0 \uc758\ud574 \ubc1c\uc0dd\ud558\ub294 hydrostatic offset\uc744\n      calibration\uc5d0 \ud3ec\ud568\ud558\ub294 \uac83\uc774\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h3>2.6 Compensated Leg System<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      Closed vessel \ub0b4\ubd80\uc5d0\ub294 liquid pressure\ubfd0 \uc544\ub2c8\ub77c\n      gas pressure\ub3c4 \uc874\uc7ac\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      Bottom pressure\ub9cc \uce21\uc815\ud558\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>bottom<\/sub>\n      =\n      P<sub>gas<\/sub>\n      +\n      \u03c1gh\n    <\/div>\n\n    <p>\n      \uc774\ubbc0\ub85c gas pressure \ubcc0\ud654\ub3c4\n      level \ubcc0\ud654\ucc98\ub7fc \ub098\ud0c0\ub0a0 \uc218 \uc788\ub2e4.\n    <\/p>\n\n\n    <h4>Differential Pressure \ubcf4\uc0c1<\/h4>\n\n    <p>\n      DP transmitter\uc758 H\uce21\uc744 vessel bottom,\n      L\uce21\uc744 top gas space\uc5d0 \uc5f0\uacb0\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>H<\/sub>\n      =\n      P<sub>gas<\/sub>\n      +\n      \u03c1gh\n    <\/div>\n\n    <div class=\"formula\">\n      P<sub>L<\/sub>\n      =\n      P<sub>gas<\/sub>\n    <\/div>\n\n    <div class=\"formula\">\n      \u0394P\n      =\n      P<sub>H<\/sub>\n      &#8211;\n      P<sub>L<\/sub>\n    <\/div>\n\n    <div class=\"formula\">\n      \u0394P\n      =\n      \u03c1gh\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        Vessel gas pressure\ub294 H\uce21\uacfc L\uce21\uc5d0 \uacf5\ud1b5\uc73c\ub85c \uc791\uc6a9\ud558\ubbc0\ub85c\n        differential pressure \uacc4\uc0b0\uc5d0\uc11c \uc81c\uac70\ub41c\ub2e4.\n      <\/strong>\n    <\/div>\n\n\n    <h4>Wet Leg<\/h4>\n\n    <p>\n      Top impulse line\uc5d0 condensate \ub610\ub294 sealing liquid\uac00\n      \ud56d\uc0c1 \ucc44\uc6cc\uc838 \uc788\uc73c\uba74 Wet Leg\ub77c\uace0 \ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>wet<\/sub>\n      =\n      \u03b3<sub>wet<\/sub>\n      h<sub>wet<\/sub>\n    <\/div>\n\n    <p>\n      Wet Leg\uc758 density\uc640 \ub192\uc774\uac00 \uc77c\uc815\ud558\uba74\n      \uc774 pressure\ub294 constant\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Wet Leg\n      \u2192 Constant Hydrostatic Head\n      \u2192 Constant Offset\n      \u2192 Calibration\uc73c\ub85c \ubcf4\uc815\n    <\/div>\n\n\n    <h4>Remote Seal<\/h4>\n\n    <p>\n      Impulse line\uc744 process\uc5d0 \uc9c1\uc811 \uc5f0\uacb0\ud558\uae30 \uc5b4\ub835\uac70\ub098\n      Wet Leg \uc0c1\ud0dc \uc720\uc9c0\uac00 \uace4\ub780\ud55c \uacbd\uc6b0\n      Remote Seal\uacfc capillary\ub97c \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Process Pressure\n      \u2192 Remote Seal Diaphragm\n      \u2192 Fill Fluid\n      \u2192 Transmitter\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h3>2.7 Tank Expert System<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      Hydrostatic level measurement\uc758 \uae30\ubcf8\uc2dd\uc740\n    <\/p>\n\n    <div class=\"formula\">\n      P = \u03c1gh\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \ub530\ub77c\uc11c pressure\uac00 \uc99d\uac00\ud588\ub2e4\uace0 \ud574\uc11c\n      level\uc774 \uc99d\uac00\ud588\ub2e4\uace0 \ubc14\ub85c \ud310\ub2e8\ud560 \uc218\ub294 \uc5c6\ub2e4.\n    <\/p>\n\n    <div class=\"grid-2\">\n\n      <div class=\"memory\">\n        <strong>\uac00\ub2a5\uc131 1<\/strong>\n        <br><br>\n        Level h \uc99d\uac00\n      <\/div>\n\n      <div class=\"memory\">\n        <strong>\uac00\ub2a5\uc131 2<\/strong>\n        <br><br>\n        Density \u03c1 \uc99d\uac00\n      <\/div>\n\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        Tank Expert System\uc740\n        Density\ub97c \uba3c\uc800 \uacc4\uc0b0\ud55c \ub2e4\uc74c\n        \uadf8 Density\ub97c \uc774\uc6a9\ud558\uc5ec Level\uc744 \uacc4\uc0b0\ud55c\ub2e4.\n      <\/strong>\n    <\/div>\n\n\n    <h4>\uc138 \uc704\uce58\uc758 Pressure<\/h4>\n\n    <div class=\"formula\">\n      P<sub>top<\/sub>\n      =\n      P<sub>gas<\/sub>\n    <\/div>\n\n    <div class=\"formula\">\n      P<sub>middle<\/sub>\n      =\n      P<sub>gas<\/sub>\n      +\n      \u03c1g(h-x)\n    <\/div>\n\n    <div class=\"formula\">\n      P<sub>bottom<\/sub>\n      =\n      P<sub>gas<\/sub>\n      +\n      \u03c1gh\n    <\/div>\n\n\n    <h4>Density \uacc4\uc0b0<\/h4>\n\n    <div class=\"formula\">\n      P<sub>bottom<\/sub>\n      &#8211;\n      P<sub>middle<\/sub>\n      =\n      \u03c1gx\n    <\/div>\n\n    <p>\n      \uc5ec\uae30\uc11c x\ub294 Bottom\uacfc Middle transmitter \uc0ac\uc774\uc758\n      \uace0\uc815\ub41c \ub192\uc774 \ucc28\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      \u03c1\n      =\n      (P<sub>bottom<\/sub> &#8211; P<sub>middle<\/sub>)\n      \/\n      gx\n    <\/div>\n\n    <div class=\"memory\">\n      \ub450 transmitter \uc0ac\uc774\uc758 \ub192\uc774 x\ub294 \ubcc0\ud558\uc9c0 \uc54a\ub294\ub2e4.\n\n      <br><br>\n\n      \ub530\ub77c\uc11c \uc774 \ub450 \uc9c0\uc810 \uc0ac\uc774\uc758 pressure difference\uac00 \ubcc0\ud558\uba74\n      liquid density\uac00 \ubcc0\ud55c \uac83\uc73c\ub85c \ud310\ub2e8\ud560 \uc218 \uc788\ub2e4.\n    <\/div>\n\n\n    <h4>Density\uac00 \ubcc0\ud558\ub294 \uc774\uc720<\/h4>\n\n    <p>\n      \uac19\uc740 liquid\ub77c\ub3c4 density\uac00 \ud56d\uc0c1 \uc644\uc804\ud788 \uc77c\uc815\ud55c \uac83\uc740 \uc544\ub2c8\ub2e4.\n    <\/p>\n\n    <ul>\n      <li>Temperature<\/li>\n      <li>Pressure<\/li>\n      <li>Concentration<\/li>\n      <li>Composition<\/li>\n    <\/ul>\n\n    <div class=\"warning\">\n      \uc5ec\uae30\uc11c density \ubcc0\ud654\ub294\n      liquid\uac00 \uc99d\ubc1c\ud558\uc5ec gas\uc640 \uc11e\uc778\ub2e4\ub294 \uc758\ubbf8\uac00 \uc544\ub2c8\ub2e4.\n\n      <br><br>\n\n      Process liquid \uc790\uccb4\uc758 \uc628\ub3c4, \ub18d\ub3c4,\n      \uc870\uc131 \ub4f1\uc774 \ubcc0\ud55c\ub2e4\ub294 \uc758\ubbf8\uc774\ub2e4.\n    <\/div>\n\n\n    <h4>Level \uacc4\uc0b0<\/h4>\n\n    <p>\n      Density\ub97c \uad6c\ud588\ub2e4\uba74\n      Bottom\uacfc Top pressure difference\ub97c \uc774\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>bottom<\/sub>\n      &#8211;\n      P<sub>top<\/sub>\n      =\n      \u03c1gh\n    <\/div>\n\n    <div class=\"formula\">\n      h\n      =\n      (P<sub>bottom<\/sub> &#8211; P<sub>top<\/sub>)\n      \/\n      \u03c1g\n    <\/div>\n\n    <div class=\"flow\">\n      Pressure Difference\n      \u2192 Density\n      \u2192 Level\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h3>2.8 Hydrostatic Interface Level Measurement<\/h3>\n\n  <div class=\"card\">\n\n    <p>\n      \uc11c\ub85c \uc11e\uc774\uc9c0 \uc54a\ub294 \ub450 \uc561\uccb4\uac00 \uc788\uc744 \ub54c\n      \ub450 \uc561\uccb4\uc758 \uacbd\uacc4 \uc704\uce58\ub97c Interface Level\uc774\ub77c\uace0 \ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Light Liquid\n      <br>\u2193<br>\n      Interface\n      <br>\u2193<br>\n      Heavy Liquid\n    <\/div>\n\n    <p>\n      Bottom pressure\ub294 \ub2e4\uc74c\uacfc \uac19\uc774 \ud45c\ud604\ub41c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P\n      =\n      \u03b3<sub>1<\/sub>h<sub>1<\/sub>\n      +\n      \u03b3<sub>2<\/sub>h<sub>2<\/sub>\n    <\/div>\n\n\n    <h4>\uc65c Total Level\uc744 \uace0\uc815\ud574\uc57c \ud558\ub294\uac00?<\/h4>\n\n    <p>\n      Pressure \ud558\ub098\ub9cc \uce21\uc815\ud558\uba74\n      pressure \ubcc0\ud654\uac00 Interface \ubcc0\ud654 \ub54c\ubb38\uc778\uc9c0\n      Total Level \ubcc0\ud654 \ub54c\ubb38\uc778\uc9c0 \uad6c\ubd84\ud560 \uc218 \uc5c6\ub2e4.\n    <\/p>\n\n    <p>\n      \uac00\uc7a5 \ub2e8\uc21c\ud55c \ubc29\ubc95\uc740 Overflow Pipe\ub85c\n      total liquid height\ub97c \uc77c\uc815\ud558\uac8c \ub9cc\ub4dc\ub294 \uac83\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      h<sub>1<\/sub>\n      +\n      h<sub>2<\/sub>\n      =\n      Constant\n    <\/div>\n\n    <p>\n      Interface\uac00 \u0394h\ub9cc\ud07c \uc62c\ub77c\uac00\uba74\n      Heavy Liquid\ub294 \u0394h\ub9cc\ud07c \uc99d\uac00\ud558\uace0\n      Light Liquid\ub294 \u0394h\ub9cc\ud07c \uac10\uc18c\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      \u0394P\n      =\n      (\u03b3<sub>1<\/sub> &#8211; \u03b3<sub>2<\/sub>)\u0394h\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        Interface \uc774\ub3d9\uc740\n        Heavy Liquid\uc640 Light Liquid\uc758\n        density \ucc28\uc774\uac00 pressure \ubcc0\ud654\ub85c \ub098\ud0c0\ub098\ub294 \ud604\uc0c1\uc774\ub2e4.\n      <\/strong>\n    <\/div>\n\n\n    <h4>Compensating Leg \ubc29\uc2dd<\/h4>\n\n    <p>\n      Total Level\uc774 \ubcc0\ud558\ub294 \uacbd\uc6b0\uc5d0\ub294\n      Upper Remote Seal\uc744 \uc774\uc6a9\ud558\uc5ec\n      Total Level\uc758 \uc601\ud5a5\uc744 \ubcf4\uc0c1\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>H<\/sub>\n      =\n      \u03b3<sub>1<\/sub>h<sub>1<\/sub>\n      +\n      \u03b3<sub>2<\/sub>h<sub>2<\/sub>\n      +\n      \u03b3<sub>2<\/sub>h<sub>3<\/sub>\n    <\/div>\n\n    <div class=\"formula\">\n      P<sub>L<\/sub>\n      =\n      \u03b3<sub>4<\/sub>h<sub>4<\/sub>\n      +\n      \u03b3<sub>2<\/sub>h<sub>3<\/sub>\n    <\/div>\n\n    <p>\n      \ucc28\uc555\uc744 \uacc4\uc0b0\ud558\uba74 \uacf5\ud1b5\ud56d\n      \\(\u03b3_2h_3\\)\uac00 \uc11c\ub85c \uc0c1\uc1c4\ub41c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      \u0394P\n      =\n      \u03b3<sub>1<\/sub>h<sub>1<\/sub>\n      +\n      \u03b3<sub>2<\/sub>h<sub>2<\/sub>\n      &#8211;\n      \u03b3<sub>4<\/sub>h<sub>4<\/sub>\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        Upper Remote Seal\ubcf4\ub2e4 \uc704\ucabd\uc5d0 \uc788\ub294 liquid column\uc740\n        H\uce21\uacfc L\uce21\uc5d0 \uacf5\ud1b5\uc73c\ub85c \uc791\uc6a9\ud558\ubbc0\ub85c\n        differential pressure\uc5d0\uc11c \uc81c\uac70\ub41c\ub2e4.\n      <\/strong>\n    <\/div>\n\n\n    <h4>Interface Transmitter Span<\/h4>\n\n    <p>\n      Interface\uac00 \uc6c0\uc9c1\uc774\uba74\n      Heavy Liquid\ub294 \uc99d\uac00\ud558\uace0\n      Light Liquid\ub294 \uac19\uc740 \ub9cc\ud07c \uac10\uc18c\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      DP Span\n      =\n      Interface Span\n      \u00d7\n      (Heavy SG &#8211; Light SG)\n    <\/div>\n\n    <p>\n      \uc608\ub97c \ub4e4\uc5b4\n    <\/p>\n\n    <div class=\"formula\">\n      Interface Span = 36 in\n    <\/div>\n\n    <div class=\"formula\">\n      SG<sub>H<\/sub> = 1.1\n    <\/div>\n\n    <div class=\"formula\">\n      SG<sub>L<\/sub> = 0.78\n    <\/div>\n\n    <p>\n      \ub77c\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      DP Span\n      =\n      36(1.1 &#8211; 0.78)\n      =\n      11.52 inH\u2082O\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>3. \uc6a9\uc5b4 \uac04 \uad00\uacc4<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\ubc29\uc2dd<\/th>\n          <th>\ubb34\uc5c7\uc744 \uce21\uc815\ud558\ub294\uac00?<\/th>\n          <th>\ud575\uc2ec \uad00\uacc4<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>Sight Glass<\/strong><\/td>\n          <td>\uc561\uba74 \uc9c1\uc811 \uad00\ucc30<\/td>\n          <td>Vessel\uacfc Gauge\uc758 \uc720\uccb4 \uad6c\uc870 \uc7ac\ud604<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Float<\/strong><\/td>\n          <td>\uc561\uba74 \uc704\uce58<\/td>\n          <td>Level \u2192 Position<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Hydrostatic<\/strong><\/td>\n          <td>\uc561\uccb4\uac00 \ub9cc\ub4dc\ub294 \uc555\ub825<\/td>\n          <td>P = \u03c1gh<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Bubbler<\/strong><\/td>\n          <td>Dip Tube Back Pressure<\/td>\n          <td>P<sub>tube<\/sub> \u2248 \u03c1gh<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Closed Vessel DP<\/strong><\/td>\n          <td>Bottom\uacfc Top Pressure Difference<\/td>\n          <td>Gas Pressure \uc81c\uac70<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Wet Leg<\/strong><\/td>\n          <td>L\uce21 Constant Head<\/td>\n          <td>Constant Offset<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Tank Expert System<\/strong><\/td>\n          <td>Density + Level<\/td>\n          <td>\u03c1 \uacc4\uc0b0 \u2192 h \uacc4\uc0b0<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Interface<\/strong><\/td>\n          <td>\ub450 \uc561\uccb4\uc758 \uacbd\uacc4<\/td>\n          <td>\u0394P = (\u03b3H &#8211; \u03b3L)\u0394h<\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <h3>Level Measurement\uc758 \ubc1c\uc804 \uacfc\uc815<\/h3>\n\n  <div class=\"flow\">\n    \ub208\uc73c\ub85c \ubcf8\ub2e4\n    \u2192 \uc704\uce58\ub97c \uc7b0\ub2e4\n    \u2192 \uc555\ub825\uc744 \uc7b0\ub2e4\n    \u2192 \ucc28\uc555\uc73c\ub85c \ubcf4\uc0c1\ud55c\ub2e4\n    \u2192 \ubc00\ub3c4\ub97c \uacc4\uc0b0\ud55c\ub2e4\n    \u2192 Interface\ub97c \uacc4\uc0b0\ud55c\ub2e4\n  <\/div>\n\n\n  <h3>Hydrostatic Measurement\uc758 \ud575\uc2ec<\/h3>\n\n  <div class=\"formula\">\n    P = \u03c1gh\n  <\/div>\n\n  <p>\n    Pressure\uac00 \uc99d\uac00\ud588\uc744 \ub54c \ub450 \uac00\uc9c0 \uac00\ub2a5\uc131\uc774 \uc788\ub2e4.\n  <\/p>\n\n  <div class=\"grid-2\">\n\n    <div class=\"memory\">\n      <strong>Density \uc99d\uac00<\/strong>\n      <br><br>\n      \u03c1 \u2191\n      \u2192 P \u2191\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>Level \uc99d\uac00<\/strong>\n      <br><br>\n      h \u2191\n      \u2192 P \u2191\n    <\/div>\n\n  <\/div>\n\n  <p>\n    \ub530\ub77c\uc11c Chapter 20 \ud6c4\ubc18\ubd80\ub294\n    \uc774 \ub450 \uc601\ud5a5\uc744 \uc5b4\ub5bb\uac8c \ubd84\ub9ac\ud558\uace0 \ubcf4\uc0c1\ud560 \uac83\uc778\uac00\ub97c \ub2e4\ub8ec\ub2e4.\n  <\/p>\n\n\n  <!-- ================================================= -->\n  <h2>4. \ud558\ub098\uc758 \uc2a4\ud1a0\ub9ac\ub85c \uc774\ud574\ud558\uae30<\/h2>\n\n\n  <div class=\"story\">\n\n    <h3>Step 1. \ucc98\uc74c\uc5d0\ub294 \ub208\uc73c\ub85c \ubcf8\ub2e4<\/h3>\n\n    <p>\n      Tank \uc548\uc758 \uc561\uccb4 \ub192\uc774\ub97c \uc54c\uace0 \uc2f6\ub2e4.\n    <\/p>\n\n    <p>\n      \uac00\uc7a5 \ub2e8\uc21c\ud55c \ubc29\ubc95\uc740 vessel \uc606\uc5d0\n      Sight Glass\ub97c \uc5f0\uacb0\ud558\ub294 \uac83\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Sight Glass\n      =\n      Tank \ub0b4\ubd80 Level\uc758 \uc9c1\uc811 \uc7ac\ud604\n    <\/div>\n\n  <\/div>\n\n\n  <div class=\"story\">\n\n    <h3>Step 2. \ub208\uc73c\ub85c \ubcf4\uc9c0 \uc54a\uace0 \uc704\uce58\ub97c \uce21\uc815\ud55c\ub2e4<\/h3>\n\n    <p>\n      \uc561\uba74\uc5d0 Float\ub97c \ub744\uc6b4\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Level\n      \u2192 Float Position\n    <\/div>\n\n    <p>\n      Turbulence\uac00 \uc2ec\ud558\uba74\n      Guide Wire\ub85c \uc6c0\uc9c1\uc784\uc744 \uc81c\ud55c\ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <div class=\"story\">\n\n    <h3>Step 3. \uc561\uccb4\uac00 \ub9cc\ub4dc\ub294 \uc555\ub825\uc744 \uc774\uc6a9\ud55c\ub2e4<\/h3>\n\n    <p>\n      \uc561\uccb4\uac00 \ub192\uc544\uc9c8\uc218\ub85d bottom pressure\ub3c4 \uc99d\uac00\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P = \u03c1gh\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c Pressure Transmitter\ub85c\n      level\uc744 \uacc4\uc0b0\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <div class=\"story\">\n\n    <h3>Step 4. Sensor\uac00 \uc561\uccb4\uc5d0 \ub2ff\uc73c\uba74 \uace4\ub780\ud558\ub2e4<\/h3>\n\n    <p>\n      Process liquid\uac00 corrosive\ud558\uac70\ub098\n      pressure port\ub97c \ub9c9\uae30 \uc27d\ub2e4.\n    <\/p>\n\n    <p>\n      \uadf8\ub798\uc11c Dip Tube\uc5d0 Purge Gas\ub97c \ub123\ub294\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>tube<\/sub> \u2248 \u03c1gh\n    <\/div>\n\n    <p>\n      \uc774\uac83\uc774 Bubbler\uc774\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <div class=\"story\">\n\n    <h3>Step 5. Closed Vessel\uc5d0\uc11c\ub294 Gas Pressure\uac00 \ubb38\uc81c\ub2e4<\/h3>\n\n    <div class=\"formula\">\n      P<sub>bottom<\/sub>\n      =\n      P<sub>gas<\/sub>\n      +\n      \u03c1gh\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c bottom pressure \ud558\ub098\ub9cc \ubcf4\uba74\n      gas pressure \ubcc0\ud654\ub97c level \ubcc0\ud654\ub85c \uc624\uc778\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <p>\n      \uadf8\ub798\uc11c DP Transmitter\ub97c \uc0ac\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      (P<sub>gas<\/sub> + \u03c1gh)\n      &#8211;\n      P<sub>gas<\/sub>\n      =\n      \u03c1gh\n    <\/div>\n\n  <\/div>\n\n\n  <div class=\"story\">\n\n    <h3>Step 6. Wet Leg\uc640 \uc124\uce58 \ub192\uc774\ub3c4 \ubcf4\uc0c1\ud55c\ub2e4<\/h3>\n\n    <p>\n      Wet Leg\uc640 Remote Seal\uc758 Fill Fluid\ub3c4\n      hydrostatic pressure\ub97c \ub9cc\ub4e0\ub2e4.\n    <\/p>\n\n    <p>\n      \ud558\uc9c0\ub9cc \ub192\uc774\uc640 density\uac00 \uc77c\uc815\ud558\ub2e4\uba74\n      \uc77c\uc815\ud55c offset\uc73c\ub85c \ucde8\uae09\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Constant Head\n      \u2192 Constant Offset\n      \u2192 Calibration\n    <\/div>\n\n  <\/div>\n\n\n  <div class=\"story\">\n\n    <h3>Step 7. \uadf8\ub7f0\ub370 Density\uac00 \ubcc0\ud558\uba74?<\/h3>\n\n    <div class=\"formula\">\n      P = \u03c1gh\n    <\/div>\n\n    <p>\n      Pressure\uac00 \uc99d\uac00\ud588\ub2e4\uace0 \ud574\uc11c\n      \ubc18\ub4dc\uc2dc level\uc774 \uc99d\uac00\ud588\ub2e4\uace0 \ub9d0\ud560 \uc218 \uc5c6\ub2e4.\n    <\/p>\n\n    <p>\n      Density\ub3c4 \ubcc0\ud560 \uc218 \uc788\uae30 \ub54c\ubb38\uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \uadf8\ub798\uc11c Bottom\uacfc Middle pressure\ub97c \uc774\uc6a9\ud558\uc5ec\n      \uba3c\uc800 density\ub97c \uacc4\uc0b0\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      P<sub>bottom<\/sub>\n      &#8211;\n      P<sub>middle<\/sub>\n      =\n      \u03c1gx\n    <\/div>\n\n    <p>\n      \uc774\ud6c4 Bottom\uacfc Top pressure\ub97c \uc774\uc6a9\ud558\uc5ec\n      level\uc744 \uacc4\uc0b0\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"flow\">\n      Density \uacc4\uc0b0\n      \u2192 Level \uacc4\uc0b0\n    <\/div>\n\n  <\/div>\n\n\n  <div class=\"story\">\n\n    <h3>Step 8. \ub450 \uc561\uccb4\uac00 \uc788\uc73c\uba74 Interface\ub97c \uce21\uc815\ud55c\ub2e4<\/h3>\n\n    <p>\n      Heavy Liquid\uc640 Light Liquid\uac00 \ud568\uaed8 \uc874\uc7ac\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \uc774\uc81c \uc54c\uace0 \uc2f6\uc740 \uac83\uc740 \uc804\uccb4 \uc561\uba74\uc774 \uc544\ub2c8\ub77c\n      \ub450 \uc561\uccb4 \uc0ac\uc774\uc758 \uacbd\uacc4\uc774\ub2e4.\n    <\/p>\n\n    <p>\n      Interface\uac00 \uc62c\ub77c\uac00\uba74\n      Heavy Liquid\ub294 \uc99d\uac00\ud558\uace0\n      Light Liquid\ub294 \uac10\uc18c\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      \u0394P\n      =\n      (\u03b3<sub>H<\/sub> &#8211; \u03b3<sub>L<\/sub>)\u0394h\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c \ub450 liquid\uc758 density \ucc28\uc774\ub97c \uc774\uc6a9\ud558\uc5ec\n      Interface \uc704\uce58\ub97c \uce21\uc815\ud560 \uc218 \uc788\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>5. Chapter 20 \ud575\uc2ec \uae30\uc5b5 \ubb38\uc7a5<\/h2>\n\n  <div class=\"memory\">\n\n    <ol>\n\n      <li>\n        <strong>\n          Sight Glass\ub294 vessel \ub0b4\ubd80\uc758 \uc720\uccb4 \uad6c\uc870\ub97c\n          \uc678\ubd80 \uad00\uc5d0 \uadf8\ub300\ub85c \uc7ac\ud604\ud558\uc5ec level\uc744 \ubcf4\uc5ec\uc900\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Float\ub294 Level\uc744 Position\uc73c\ub85c \ubcc0\ud658\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Hydrostatic Level Measurement\uc758 \ucd9c\ubc1c\uc810\uc740\n          P = \u03c1gh\uc774\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Bubbler\ub294 bubble \uac1c\uc218\ub97c \uce21\uc815\ud558\ub294 \uac83\uc774 \uc544\ub2c8\ub77c\n          \ub0ae\uc740 purge flow\uc5d0\uc11c \ud615\uc131\ub418\ub294 back pressure\ub97c \uce21\uc815\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Closed Vessel\uc5d0\uc11c\ub294 DP Transmitter\ub97c \uc0ac\uc6a9\ud558\uc5ec\n          gas pressure\uc758 \uc601\ud5a5\uc744 \uc81c\uac70\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Wet Leg\uc640 Remote Seal\uc758 \uc77c\uc815\ud55c liquid head\ub294\n          constant offset\uc73c\ub85c calibration\ud560 \uc218 \uc788\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Density\uac00 \ubcc0\ud558\ub294 process\uc5d0\uc11c\ub294\n          pressure \ud558\ub098\ub9cc\uc73c\ub85c level\uc744 \uc815\ud655\ud558\uac8c \uad6c\ud560 \uc218 \uc5c6\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Tank Expert System\uc740 \uace0\uc815\ub41c \ub192\uc774\ucc28\uc758 pressure difference\ub85c\n          density\ub97c \uba3c\uc800 \uad6c\ud55c \ub4a4 level\uc744 \uacc4\uc0b0\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Interface Measurement\uc5d0\uc11c\ub294 Heavy Liquid\uac00 \uc99d\uac00\ud55c \ub9cc\ud07c\n          Light Liquid\uac00 \uac10\uc18c\ud558\uba70,\n          \ub450 liquid\uc758 density difference\uac00 pressure span\uc744 \uacb0\uc815\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n    <\/ol>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>6. \ucd5c\uc885 \uc554\uae30 \uad6c\uc870<\/h2>\n\n  <div class=\"flow\">\n    Sight Glass\n    <br>\u2193<br>\n    Float \/ Displacement\n    <br>\u2193<br>\n    Hydrostatic Pressure\n    <br>\n    P = \u03c1gh\n    <br>\u2193<br>\n    Bubbler\n    <br>\u2193<br>\n    DP Compensation\n    <br>\u2193<br>\n    Wet Leg \/ Remote Seal\n    <br>\u2193<br>\n    Density Compensation\n    <br>\u2193<br>\n    Interface Measurement\n  <\/div>\n\n\n  <div class=\"memory\">\n\n    <strong>\ud55c \ubb38\uc7a5 \uc815\ub9ac<\/strong>\n\n    <br><br>\n\n    Chapter 20\uc740 \uc561\uba74\uc744 \uc9c1\uc811 \ubcf4\ub294 Sight Glass\uc5d0\uc11c \uc2dc\uc791\ud558\uc5ec,\n    Float\ub85c \uc704\uce58\ub97c \uce21\uc815\ud558\uace0,\n    \uc815\uc218\uc555 P = \u03c1gh\ub97c \uc774\uc6a9\ud558\uc5ec Level\uc744 \uacc4\uc0b0\ud558\uba70,\n    Closed Vessel\uc758 Gas Pressure\uc640 Wet Leg\ub97c \ucc28\uc555\uc73c\ub85c \ubcf4\uc0c1\ud558\uace0,\n    \ub9c8\uc9c0\ub9c9\uc5d0\ub294 Density \ubcc0\ud654\uc640 Liquid-Liquid Interface\uae4c\uc9c0\n    \uacc4\uc0b0\ud558\ub294 \uacfc\uc815\uc73c\ub85c \ubc1c\uc804\ud55c\ub2e4.\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <div class=\"keywords\">\n    Sight Glass, Hydrostatic Pressure, Bubbler, Density Compensation, Interface Level\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\/09\/Lessons_In_Industrial_Instrumentation-3-1.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Lessons_In_Industrial_Instrumentation-3\uc758 \uc0bd\uc785.\"><\/object><a id=\"wp-block-file--media-c23edc1a-b117-4067-84c1-0a00a475dcd5\" href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/09\/Lessons_In_Industrial_Instrumentation-3-1.pdf\">Lessons_In_Industrial_Instrumentation-3<\/a><a href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/09\/Lessons_In_Industrial_Instrumentation-3-1.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-c23edc1a-b117-4067-84c1-0a00a475dcd5\">\ub2e4\uc6b4\ub85c\ub4dc<\/a><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Chapter 20. Continuous Level Measurement \uc6a9\uc5b4 \uc815\uc758 \u2192 \uc6a9\uc5b4 \uac04 \uad00\uacc4 \u2192 \uc2a4\ud1a0\ub9ac \u2192 \ud604\uc7a5 \uc801\uc6a9 1. Chapter 20 \uc804\uccb4 \ud750\ub984 \uc6a9\uae30 \uc548\uc5d0 \ub4e4\uc5b4 \uc788\ub294 \uc720\uccb4\uc758 \ub192\uc774\ub97c \uc5b4\ub5bb\uac8c \uce21\uc815\ud560 \uac83\uc778\uac00? \uc9c1\uc811 \uad00\ucc30 \u2192 \uc704\uce58 \uce21\uc815 \u2192 \uc815\uc218\uc555 \uce21\uc815 \u2192 \ubcf4\uc0c1 \u2192 \ubc00\ub3c4 \uacc4\uc0b0 \u2192 Interface \uce21\uc815 Level measurement\ub294 \uc561\uccb4\uc758 \ub192\uc774\ub97c \uc9c1\uc811 \ubcf4\ub294 \uac83\uc5d0\uc11c \uc2dc\uc791\ud55c\ub2e4. \uac00\uc7a5 [&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":[2192,2193,2191,2194,2190,1528],"class_list":["post-9529","post","type-post","status-publish","format-standard","hentry","category-1185","tag-bubbler","tag-density-compensation","tag-hydrostatic-pressure","tag-interface-level","tag-sight-glass","tag-1528"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9529","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=9529"}],"version-history":[{"count":3,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9529\/revisions"}],"predecessor-version":[{"id":9533,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9529\/revisions\/9533"}],"wp:attachment":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/media?parent=9529"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/categories?post=9529"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/tags?post=9529"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}