102 The Relatioship Betee Gas Ad Pressure (SF6) Whe the gas is i the temperature belo the codesig poit, de poit measuremet is ot available This gas codeses o the mirror, the figure belo idicates the relatioship betee gas (SF6) ad pressure Chilled Mirror De Poit Istrumet c m m DP29-40 o c o DP29-60 c k t e DP29-70 t e d DP29-SF6 k a e l t d a l Fig 102 The Relatioship Betee Gas ad Pressure (SF6) 10
Cotets 1 Itroductio 1 2 Specificatios 1 3 Measurig Priciple 2 4 Pael Descriptio 3 41 Frot Pael 3 42 Back Pael 5 5 Start-up Commissioig 5 51 Device State 5 52 Mirror Cleaig 5 53 Test Gas Supply System (Sample Gas Ijectio Tube) 6 54 Testig Field Istallatio 6 6 Measuremet 6 61 Preparatio 6 611 Device Coectio 6 612 Measuremet Uder System Pressure 6 613 Measuremet Uder Barometric Pressure 6 62 Measuremet 6 7 Refrigeratio Check 7 8 Mirror Check Ad Lamp Brightess Adjustmet 7 9 Fault Aalysis 8 10 Appedix 9 101 Moisture Cotet Coversio Of SF6(PPM) 9 102 The Relatioship Betee Gas Ad Pressure (SF6) 10 Cotiued Factors Causig Measuremet Error 9 The Mirror Check Idicator light is ot stable, the light fluctuates i the cotamiated area, de poit is displayed ustably (Probably SF6 is i a liquefied state) 10 Appedix 101 Moisture Cotet Coversio Of SF6(PPM) Note, 1Mpa=10bar, 1ppmg=ppmv/81 Solutios If possible, measure uder atmospheric pressure (See Fig 102) Fig 101 Moisture Cotet Coversio Of SF6 9
3 Clea the Mirror 4 Re-istall the Measuremet Probe 5 If the Mirror Check Idicator light i the clea area (clea), the cleaig process is completed If it is still i the cotamiated area or edge of the clea area, cotiue to the folloig operatio (6) 6 Adjust the Light Itesity Hole so that the Mirror Check Idicator light is i the middle of the clea area 7 If the operatio does ot ork (the Light Itesity Adjustig Hole does ot make a differece), it is ecessary to clea the Lamp ad the LDR photosesitive resistace iside the Measuremet Probe 9 Fault Aalysis Factors Causig Measuremet Error 1 There is udercoolig poit i the system, (belo the de poit) codesatio iside the istrumet 8 Solutios Dry the system ith gas (Istrumet temperature should ot be loer tha eviromet temperature) 2 The Ilet Tube is damp Blo the tube ith dry air for more tha 10 miutes 3 The Coector is damp Blo-dry the coector (Above 60 ) 4 There is greasy dirt iside the Ilet Tube or the Coector Clea them ith Acetoe, the dry ith compressed gas 5 Temperature leak out of the istrumet Use soap-suds to check hether each coector is istalled correctly 6 Quality of ilet gas is ot good Do ot use the tubes made of Rubber, Nylo or PVC Whe the tested de poit is as lo as -40, Polyethylee or Brass tube is available Whe the de poit is as lo as -40, FEP (Fluoriated Ethylee Propylee), PTFE (Polytetrafluoroethylee) or Stailess Steel tube is available 7 Pressure Ifluece See Fig 102 8 The chage of gas flo The slight fluctuatios of gas flo ill ot affect the measuremet results (about 20-50L/HR) If the gas flo is too high, ca cause some loss of accuracy If the gas flo is too lo, the measuremet time ill be exted To see the ext page, cotiued 1 Itroductio DP29 is a multifuctioal, portable de poit humidity meter, especially desiged for field use The typical applicatio of this equipmet is the de poit measuremet of SF6 gas The pressure rage is from 10mbar to 10bar (1kPa to 1Mpa) he measurig The differetial pressure betee ilet ad outlet is 10mbar (1kPa), it is effective for the sample gas measuremet If the gas pressure is too lo or the sample gas as measured i a closed pipelie, choose a pump for measuremet The measuremet is based o the priciple of chilled mirror Due to the elimiatio of the error caused by iertia ad laggig of the system, the actual temperature measuremet of direct ad accurate is guarateed The system is stable, does ot eed to be repeatedly calibrated I Freezig poit detectig method, oly eed to simply press butto, the equipmet is able to self-test of accuracy at 0 C Stadard cofiguratio of DP29 equipmet icludes a prepositive tight pressure measurig probe ith three-stage Peltier coolig As for the corrosive gas, pipelie should be made of PTFE or stailess steel There is a built i electroic flo meter, moitorig sample gas flo The system provides a ±10mv/ C aalog output for recordig or remote cotrollig DP29-40 is specifically desiged for air de poit measuremet It is applicable to stadard referece for electroic compoet durability, de poit cotrol for firig furaces, de poit cotrol for fuel cell test system, etc DP29-SF6 is specially for the measuremet of Sulfur Hexafluoride (SF6) DP29-60 is a stadard type It applies to stadard referece for laboratory calibratio, moisture cotrol for ceramic firig furaces, humidity cotrol for thermo-hygrostat chamber DP29-70 is a high-ed type It is suitable for moisture cotrol of dryig process, productio process of lithium io battery, measuremet of gas ith lo de poit NOTICE The applicatio above is for referece oly, model selectio depeds o the specific situatio 2 Specificatios Measuremet Rage: Surroudig Temperature 10-60 -60 5 20 35 DP29-40 DP29-60 DP29-60 DP29-70 -40-40 -35-30 Measuremet Rage -60-60 -55-55 -45-45 Accuracy: ±02,±1 Digit Repeatability: ±01,±1 Digit Display: Digital Resolutio: 01 Default Output: USB Optioal Output: ±10mv/, (0 =0mv) or 4-20mA Measuremet Priciple: Chilled Mirror Refrigeratio: Semicoductor Refrigeratio Ilet Flo: 15-60L/h, Geerally 30-40L/h 1-70 -65-60 -50 Ilet Pressure: 10mbar-10bar(1kpa-1Mpa) Respose Time: 2 /Secod (Maximum) Pump: Optioal Accessory Mirror Check: Press the Mode Coversio Key to mirror check mode ( CH o the display), ad check maually Istrumet Check: Press the Test Coolig Key, ope the measuremet probe, ad check maually at mirror check mode
Voltage: 220VAC±10%, 50/60HZ Poer Cosumptio: About 160 Watts Surroudig Temperature: 0-50 Surroudig Humidity: <90%, No Codesatio Weight: About 722kg Dimesio: 342(W)x140(H)x326(D) mm The stadard cofiguratios of SF6 de poit istrumet are as follos: * Mai Uit * Ilet Tube (FEP,3m), With Coector * Istructio Maual * Packagig Box Notice: The equipmet ith stadard cofiguratio is able to measure SF6 ad air oly, for H2 or other gas might eed extra order 3 Measurig Priciple VOLTAGE 220VAC 50/60Hz 8 9 10 11 12 POWER SUPPLY UNIT 4 LAMP LAMP STABILIZER BLOCK 5 LDR 3 PT-100 2 MIRROR 1 PELTIER-BATTERY 6 COOLER 7 VENTILATOR ±5/±15VDC STABILIZER- BLOCK Fig 3 Measuremet Priciple 2 DEW POINT- TEMP AMPLIFIER 13 14 PELTIER OUTPUT STAGE DEW POINT- INDICATOR C DP MIRROR CHECK INDICATOR 15 PELTIER CONTROLLER BLOCK * Check the mirror coditio, the Mirror Check Idicator should be i the middle of the clea area * Press the Mode Coversio Key to ME Mode The device begis to chill do to the de poit, the Mirror Check Idicator moves toard the cotamiated area * Wait for the readig o the De Poit Idicator stable * Read Focus: Whe testig more tha oe spot, it is ecessary to cofirm every spot Because i the eviromet ith high humidity, he the measurig spot is chaged, the gas samplig tube loop ad the ambiet air are still closed It takes a little loger time for ultra lo de poit temperature measuremet I ormal measuremet, the readig ill shock 1-3 times aroud the real de poit 7 Refrigeratio Check A simple test ca be used to check the measuremet accuracy If the measured results ad predicted values differ too far, or cosider that the istrumet has fault It is ecessary to test Procedure: 1 Discoect the gas samplig tube or close the Sleeve Cotrol Valve 2 Fully ope the Flo Cotrol Valve 3 Remove the Measuremet Probe 4 Plug i ad sitch o 5 Press ad hold the Test Coolig Key ad drop the mirror temperature i the rage of -25 to -30 (see the De Poit Idicator) 6 Blo at the mirror to frost 7 Release the Mode Coversio Key to rise the mirror temperature 8 If the mirror temperature rises too fast, the curret mirror temperature idicatio ill lag behid Therefore, rise the mirror temperature sloly before reachig 0, ad cool for a hile 9 Watch the Mirror ad the Temperature Idicator carefully The frost layer o the Mirror should be melted ito drops of ater at 0 If this pheomeo appears, the device idicates temperature correctly 8 Mirror Check Ad Lamp Brightess Adjustmet The Mirror must be cleaed regularly Whe the Mirror Check Idicator is i the cotamiated area (i the Mirror Check Mode), idicatig the Mirror is cotamiated, it is ecessary to clea the Mirror Either Les tissue or cotto is available to ipe the Mirror, hile et toel is ot available If ecessary, high purity alcohol is admitted For the light source Lamp ad the photosesitive resistace LDR, soft cotto sab (Q shaped sab) is available Procedure: 1 Close the Sleeve Cotrol Valve 2 Ope the Measuremet Probe 7
53 Test Gas Supply System (Sample Gas Ijectio Tube) The material selectio of gas ijectio tube ad proper istallatio are importat Improper material of gas ijectio tube effects gas temperature, causig icorrect test results * Rubber, Nylo or PVC, material hich is permeable to ater vapor is ot available * Whe tested de poit is as lo as -40, Polyethylee or Brass tube is available * Whe the maximum operatig pressure is 10bar, use PE (Polyethylee), FEP or PTFE tube (diameter 4 X 6mm) * The maximum operatig pressure for Stailess Steel tube is 250bar (25 Mpa) The samplig gas ijectio tube should be as short as possible The temperature of tube must be higher tha the de poit of the ilet gas, eve i extreme coditios (codesatio i tube = false measuremet) 54 Testig Field Istallatio A typical istallatio for SF6 measuremet is as belo Fig 5 A Typical Istallatio For SF6 Measuremet 1 Gas Cotaiers (High Pressure 5 Sleeve Cotrol Valve Sitch, Gas Cyliders Etc) 6 Coector (Socket) 2 Samplig Coector 7 Coector (Plug) 3 Adapter 8 The De Poit Istrumet 4 Samplig Tube 6 Measuremet 61 Preparatio 611 Device Coectio Firstly coect the istrumet ith the samplig spot, ad plug it i 612 Measuremet Uder System Pressure * Close the Flo Cotrol Valve fully * Ope the Sleeve Cotrol Valve fully * Ope the Flo Cotrol Valve sloly till the gas flo idicated gets i the rage of 30-40L/HR 613 Measuremet Uder Barometric Pressure * Close the Sleeve Cotrol Valve fully * Ope the Flo Cotrol Valve fully * Ope the Sleeve Cotrol Valve sloly till the gas flo idicated gets i the rage of 30-40L/HR 62 Measuremet * Press the Poer Sitch Key to sitch o * Press the Mode Coversio Key to the CH Mode 6 The measuremet probe maily cosists of Peltier-Battery (Thermoelectric heatig pump) (1), Mirror (2), Pt-100 Sesor (3) The temperature sesor is iside the mirror, coected ith the refrigeratio side of Peltier-Battery The heat geerated by refrigeratio of Peltier-Battery is rejected by the Cooler (6) ad the adjacet Vetilator (7) De poit detectio is carried out by the optical system cosists of Lamp (4) ad photosesitive resistace LDR (5) The Peltier Cotroller (15) process sigals geerated by the photosesitive resistace ad trasmit them to the Peltier Output Stage (14), so as to form a layer of de o the mirror Temperature sigal produced by PT-100 Sesor (3) is trasmitted to the De Poit-Temp Amplifier (11) The measuremet result is displayed o the De Poit-Idicator DP (12) The slight ad tiy differece i brightess of Lamp (4) ill actually chage the measuremet result I order to avoid a mistake, Lamp Stabilizer-Block (9) provides a accurate voltage supply The additioal Stabilizer-Block (10) chages AC to DC ad geerates the required ±15V DC voltage for sub-cotrollig The Poer Supply (8) is composed of trasformer ad rectifier 4 Pael Descriptio 41 Frot Pael 4-1 Poer Sitch Key 4-2 Uit Coversio Key 4-3 De Poit Idicator 4-4 Test Coolig Key 4-5 Mode Coversio Key 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13 Fig 41 Frot Pael Diagram 4-6 Flo Idicator 4-7 RS-232 Iterface 4-8 Light Itesity Hole 4-9 Gas Selectio Key 4-1 Poer Sitch Key Press the Poer Sitch Key to sitch o the istrumet 4-2 Uit Coversio Key Press the Uit Coversio Key to perform uit coversio 3 4-10 Mirror Check Idicator 4-11 Gas Ilet 4-12 Flo Cotrol Valve 4-13 Measuremet Probe
4-3 De Poit Idicator ( De Poit) The De Poit Idicator display the actual de poit temperature i cetigrade 4-4 Test Coolig Key The key is used to test the accuracy of istrumet at 0 For details see 7 Refrigeratio Check 4-5 Mode Coversio Key (CH / ME) The key mode coversio (CH / ME) I the mode of ME, the Peltier Coolig System begis to chill do While i the mode of CH, the Peltier Coolig System stops orkig 4-6 Flo Idicator Idicatig light display the flo i L/HR (Litre/Hour) If the flo is less tha 15 L/HR, the idicator light bliks at 15 If the flo is greater tha 60 L/HR, the idicator light bliks at 60 4-7 RS-232 Iterface Usig RS-232 data cable for coectio, data trasmissio betee the istrumet ad PC is available 4-8 Light Itesity Hole I the CH Mode after the mirror is iped up, if the light of Mirror Check Idicator is ot i the middle of the clea area, isert a scredriver ito the hole for adjustmet, so as to tur the idicatig light to the clea area (area divisio of Mirror Check Idicator see 4-10) 4-9 Gas Selectio Key Whe measurig differet kids of gas, press the key for selectio 4-10 Mirror Check Idicator Iside the measuremet probe, the light, geerated by lumious tubes ad reflected by the mirror, is trasmitted to the photosesitive resistace, the idicator is divided ito clea area ad cotamiated area (the left 7 grids represet cotamiated area, the right 3 grids represet clea area) If the idicator lights i the middle of the clea area, idicatig total reflectio, the mirror is clea he codesig The eaker is the reflected light (the higher degree is the mirror polluted), the more close to the cotamiated area is the idicator Whe the istrumet is i the CH Mode, the idicator light must be i the middle of the clea area If cotamiated, the mirror must be cleaed, the adjust the light itesity hole for correctio Whe the istrumet is i the ME Mode, the mirror starts to chill do Whe the temperature drops to de poit, de or frost colum crystal is formed, the idicatig light moves to cotamiated area from clea area 4-11 Gas Ilet The Gas Ilet Tube is coected ith the Coector o the device 4-12 Flo Cotrol Valve The valve cotrols preset gas flo 4-13 Measuremet Probe After the loop pressure of gas i the istrumet is released, ati-clockise rotate the measurig probe to ope it, the iteral PTFE tube is also removable The Photosesitive Resistor is coected o left, ad the Lamp is coected o the right The Mirror is istalled betee the gas ilet (top) ad the gas outlet (bottom) 42 Back Pael 4-14 Vetilator 4-15 Gas Outlet 4-14 4-15 4-16 4-14 Fig 42 Back Pael Diagram 4-14 Vetilator The Vetilator is used to cool do the Measuremet Probe Whe the device is electrified, the Vetilator rotates cotiuously 4-15 Gas Outlet For the measuremet of air ad harmless gas, the gas outlet is ope to the atmosphere For the measuremet of corrosive gas or toxic gas, it is better to take measuremet i closed loop, the gas outlet should be coected ith the correspodig gas tube 4-16 DC Poer Output 12V The output of DC poer supply 4-17 Poer Socket For the coectio betee the istrumet ad poer source 4-17 4-16 DC Poer Output 12V 4-17 220V Poer Socket 5 Start-up Commissioig 51 Device State If the istrumet has ot bee used for a period of time, it is ecessary to adjust before use All of the tubes ad the coectig sleeve ca ot be sealed or filled ith dry gas, hoever, must be blo for 10 miutes ith dry N2, O2 or SF6 (the maximum pressure 10bar/Mpa) Ope the Flo Cotrol Valve completely, sloly ope the Sleeve Cotrol Valve for 40L/HR gas flo required Use the electrical drier to blo-dry coectors ad coectios 52 Mirror Cleaig Before use, sab the mirror ith eutral tissue paper or cotto (ithout ay solvet) Ad the reistall the frot part of the Measuremet Probe, coect the poer supply ad sitch o, press the Mode Coversio Key to CH Mode The idicatig light should be i the middle of clea area If ecessary, adjust the light itesity hole so that the idicatig light is i the appropriate positio (see 8) 4 5