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Operating Manual Dextens Thermo Conductivity Sensors

1. lf after cleaning re cleaning and retesting the sensor is still not performing well we recommend you contact Dextens Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 17 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch
2. 4 Trouble shooting Even if Dexens sensors have been designed to reduce the sources of trouble some harsh working condition may lead to sensor malfunction This chapter is here to give some tips to find and correct the problem 4 1 Calibration outside of the defined range e Calibration below 80 it is possible that the reservoir is overfilled Open and close the reservoir to reduce pressure and re measure efficiency e Calibration above 120 membrane is probably too tight Place in warm water overnight and re measure efficiency 4 2 Punctured Membrane A common problem with our sensor is that the membrane is fragile and can be easily punctured or torn when not protected by the protective grill The symptoms of this problem are reading that are not going down or very slowly The only response to this is to thoroughly clean the sensor and replace the membrane When the membrane has been broken the sampling liquid enters the reservoir To get a fully working sensor you will remove all traces of the liquid 4 3 Empty Electrolyte Reservoir Another frequent problem is that the electrolyte leaks out of the reservoir This happens after bad maintenance when the operator has not completely closed the reservoir But the effect of this problem can sometimes be detected after a quite long time because of a small leak The symptoms of this problem are a sensor that is not measuring anything and which becomes very sensitive to pressure changes To co
3. slowly with an even but firm pressure You will feel and hear the tightening ring click into place Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 13 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration The attached membrane will look as follows 3 5 Reassembly Replacing washers dacron and grill lt is important to place the various protective cap components in the correct order 1 Place 2 tefzel washers in the cap 2 Place the grill Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 14 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration 3 Place the dacron gauze pastille 4 Place the silicone washer Replacing the protective cap Finally replace the protective cap by screwing it back onto the sensor head Take care that the components within the cap remain in place Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 15 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration 3 6 Calibration The Dextens sensors are sold pre calibrated and there should be no need to calibrate them between service intervals For calibration process please refer to the operating manual of Dextens TC instruments Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch 16
4. with a new one If the support disk is removed the delicate sensing element is exposed Do not touch it even with a tissue bonding wires would be irreversibly damaged Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 10 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration You are now ready to replace the membrane Stand the sensor on a flat bench surface so that it rests on its back end with its working end facing up Take the membrane installation tool from the maintenance kit and separate it into its two parts Attach the tightening ring to the inner part as shown in the image on the right Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 11 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration Place the lower part of the tool onto the sensor head as shown Select a membrane from the maintenance kit Take care do NOT touch the middle surface of the membrane Using a set of tweesers place the membrane in the installation tool as shown Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 12 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration The membrane should be evenly spaced centrally within the support Attaching the membrane Place the upper section with the tightening ring over the lower part of the tool and press down
5. DE OF THE DEFINED RANGE sccscceceececcecceccccccuccecccuccucaecucaececaucuceecacsuesecaesuuaueaesaeeetaueaesenes 17 4 2 PUNCTURED MEMBRANE EE 17 4 3 EMPTY ELECTROLYTE HEerEpvOmp LALALE EREREAEREAEAEAEAERE RARER EAER ERE REKEREKE nanana nt 17 4 4 OT HY e RE 17 4 5 SLOW SENSOR EEN 17 Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 3 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch 1 General Information 1 1 Disclaimer Please read and understand the user manual before installing and using the products described herein It is also recommended to follow the safety recommendations from this manual The material in this manual is for informational purposes only The products it describes are subject to change without prior notice due to the manufacturer s continuous development program Dextens makes no representations or warranties with respect to this manual and shall not be liable for any damages losses costs or expenses direct indirect or incidental consequential or special arising out of or related to the use of this manual All rights reserved No part of this manual may be used or reproduced in any form or by any means without prior written permission of Dextens 1 2 Symbols and Conventions The danger sign below indicates actions or configurations that may be dangerous for the user or that may lead to wrong measurements Read and understand these paragraphs before starting to use
6. e remember that the TC sensors do not require regular servicing While the membrane replacement procedure on these sensors is similar to that of the electrochemical sensor no chemical or electrochemical cleaning is required and furthermore membrane changes need be performed far less often if at all 3 2 What to maintain There are just two components which should require maintenance on a TC sensor The Dacron gauze filter The membrane We recommend that whenever the membrane is changed the Dacron gauze filter is also changed 3 3 Disassembly Remove the sensor from its flow chamber Before removing the sensor from a sensor socket make sure to first drain all liquid from the pipe If you are using a model 74001 00 28mmTuchenhagen insertion extraction valve the sample is sealed off automatically as the sensor is withdrawn Holding the sensor handle in one hand carefully unscrew the collar and pull the sensor out of the mounting sensor socket flow chamber or other mounting see section 2 2 You can stop the opening by replacing the sensor with the stainless steel plug and collar supplied for this purpose Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 8 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration After removing the sensor from the line unscrew the protection cap Lift off the cap taking care not to lose the grill and washers inside No
7. i E A i 6 l Du poi Dextens Thermo d i av 9 Conductivity Sensors EN b v0 d Type 52101 54101 55101 Operating Manual May 2012 Dextens Table of Content 1 GENERAL INFORMA ON WEEN 4 1 1 DINNI E 4 1 2 SYMBOLS AND CONVENTIONS cccceccececcccececcececcecccceceucecuececacauceceuecsunecuuaecseausueueseuseaeuecauaecuenecsuaessuaessuaeaucaeaecsunerass 4 1 3 IN REPAIRS ee 4 1 4 CE CONFOPMITY EE 4 2 INTRODUC TION BEEN 5 2 1 CONTENT OF PACKAGE THERMO CONDUCTIVITY TC SENSOR cccccccssssssceceseeeeeeeesseceeeeeeeeaeessseeeeseeeeueasseeeeeeeeeeaas 5 2 2 PG GS OS ore c cca stacien EES 5 2 3 STORAGE INFORMATION 6 2 4 TECHNICAL SPECIFICATIONS 0ccecceccecccecceccececucceccececuccecuecuecausucaecuecaececeucuecuuaucsenecsecuusueueceesuuaueaesaesuuaeceeeuesauaesanss 6 2 5 SENSOR DIMENSIONS icccawersacxecdsacesadeedesnardcvsessetedcevicd cudexedesdvneasedac lt xandecseveeidadvardod seveaastedes daccseocexecvsiBavadscatarcandiarendecsas 7 2 6 PRINCIPLE OF MEAGUpBEMENT aranan anaon raene n ELELLA EAER EAELE LELARA REAREA AERE AA LARARE LALALALA LECACACE EREA A EAEan nna 7 3 MAINTENANCE AND CALIBRATION ee KN ENKE ENEE REENEN ENEE REENEN ENKE ENNEN K NENNEN ENER KEEN ENEE E EEN 8 3 1 PINTO DUG Oe EEN 8 3 2 ee IN UI NEEN 8 3 3 IG SS Ee EE 8 3 4 REPLACING THE EES 10 3 5 oiee a i E E an A EE E E A A E A E E EE A A E E E 14 3 6 ETON e E EE E EE sauna EEE EE EA EES A EEA ETE E E 16 4 TROUBLE SHOOTING EEN 17 4 1 CALIBRATION OUTSI
8. n les Ouates m Switzerland 7 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch 3 Maintenance and Calibration 3 1 Introduction This guide explains how to clean and carry out basic maintenance of Dextens thermo conductivity TC sensor models There is no definitive rule to when you clean a sensor Nor is there is a standard service interval However you should clean a sensor when It is slow It is noisy The calibration is out of range It is visibly dirty Dextens offers a maintenance kit and cleaning unit which provides all the components necessary to complete the cleaning and basic maintenance of a sensor Periodically check the sensor calibration using a known standard As long as the reading is 1 of the expected value no action needs to be taken If the calibration has changed 1 10 perform a new calibration If the deviation is more than 10 of the original values a membrane service will be required Only change the sensor membrane when troubleshooting indicates that the membrane has failed A visual inspection of the sensor face will also reveal any problem like dust deposits or accumulation of dirt onto the protection grill Please carry out the following operations in a clean dry place in order to avoid the possibility of blocking or damaging the stainless steel grill in the sensor s face or of allowing water to get into the sensor Very Important Note Unlike your O2 sensor pleas
9. o a process instrument Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 5 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Part Nr 87410 87411 Sensor maintenance kit 2 3 Storage Information During a long period of inactivity more than 1 week the sensor should be removed wiped dry and stored properly For shorter periods of inactivity weekends it is not necessary to remove the sensor it may stay in place with the instrument turned on and with purge gas supplied Storage instructions rinse possible deposits on sensor s head rinse under tap water wipe sensor head dry put a small silica desiccant bag inside the storage cap put the storage cap in place store the sensor in a safe dry place temperature of storage place must be stable and correspond to common indoor levels Rapid temperature changes must be avoided for instance air conditioning turned on and off daily AN they can create condensation inside the sensor s cell and damage the electronics inside 2 4 Technical Specifications Sensor Model CO2 Sensor serial number 52401 52201 52201 52501 en ES Cycle time 20 sec Weight 0 6 kg Enclosure protection IP65 Material in contact l ANSI 316L PFA or Tefzel with sample 3m standard length optional extension up to 1000 m Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 6 T 41 22 8848306 F 41 223424860 info dextens ch www de
10. rrect the problem do a complete maintenance taking much care to completely close the electrolyte reservoir 4 4 Dirty Sensor After some time in normal use the sensors becomes dirty They are much slower to go down and the response signal is quite noisy The only thing to do is a maintenance some times with a chemical clean see 4 4 4 4 5 Slow Sensor If when completing the sodium sulfite test the sensor does not reach 10 ppb in 10 minutes AND 0 4 ppb in 60 minutes then let the sensor sit for 1 hour connected to the instrument This will allow the sensor to consume any oxygen which may reside in the electrolyte e Inspect the sensor for air bubbles If there are none then retest the sensor speed If there are bubbles you must rework the reservoir to remove them either by topping up the reservoir or completely refilling it Note if you completely refill the reservoir you should recalibrate the sensor If the sensor is still not delivering to specification bullet point 1 above allow it to sit overnight connected to the instrument and retest If after testing and allowing the sensor to sit either for an hour or overnight performance is still not to specification check the following Is the membrane clean Are there no bubbles in the reservoir Inspect the cathode guard and anode are they clean Even if they appear clean re clean the sensor we recommend both aggressive and basic cleaning and recalibrate and retest
11. te never remove the protection cap unless the membrane has failed Dry the sensor thoroughly with a paper towel The protective cap has a number of components which should come out with the cap when it is removed To remove the Dacron gauze simply gently push the contents of the protective cap apart Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 9 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch Maintenance and Calibration Note the different components and washers With the exception of the Dacron gauze these can usually be re used 1 Protective cap 2 Tefzel washers 3 Grill 0 2 mm 4 Dacron Gauze 5 Silicone washers 3 4 Replacing the Membrane Remove the membrane tightening ring with the tool Place the larger section of the tool over the ring and pull to tool until it is tight around the rings middle section Now just lift the removal tool and the membrane and tightening ring will come free Take care that the protective pastille remains in place it can fall out If it does fall out simply replace it with great care DO NOT TOUCH the chip It is extremely delicate and easily damaged Remove the old membrane to reveal the stainless steel grill in the sensing face The grill must be clean and dry If necessary wipe it with a paper tissue Be careful not to drop the membrane support disk If the mesh covering this support disk is damaged replace the support disk
12. the described material 1 3 Services and Repairs No sensor components can be repaired by the user Only personnel from Dextens or its approved representative s is are authorized to attempt repairs to the sensor and only components formally approved by the manufacturer should be used Any attempt at repairing the sensor in contravention of these principles could cause damage to the sensor and corporal injury to the person carrying out the repair It renders the warranty null and void and could compromise the correct working of the sensor and the electrical integrity or the CE compliance of the sensor 1 4 CE Conformity The TC sensors instruments are manufactured conforming to the requirements of the electromagnetic compatibility directive 89 336 CEE and the low voltage directive 73 23 CEE Dextens SA m 18 Chemin des Aulx m 1218 Plan les Ouates m Switzerland 4 T 41 22 8848306 F 41 223424860 info dextens ch www dextens ch 2 introduction 2 1 Content of Package Thermo Conductivity TC Sensor When ordering a TC sensor you will receive the following item 52201 H2 sensor 52401 CO2 sensor 52501 N2 sensor Physical Description 1 Purge Gas Outlet 2 Protection Cap 3 Purge Gas Inlet 4 Output Connection to instrument 5 Input Connection from in line temperature sens This user manual 2 2 Accessories Depending on your order additional accessories can be delivered Part Nr 75502 mmm Cable for connecting the sensor t
13. xtens ch Introduction 2 5 Sensor Dimensions Length 159 mm Max Diameter 59 mm Min Diameter 27 95 mm M42x1 5 D 27 95 mm 2 6 Principle of Measurement This thermal conductivity sensor is designed to continuously measure Carbon dioxide CO2 Nitrogen N2 or Hydrogen H2 Measurements are possible in dissolved or gaseous applications The sensor operates on the following principle the gas to measure diffuses from the sample into a micro volume contained in the sensor through a semi permeable membrane and comes into contact with a gas thermal conductivity detector The temperature and the change in thermal conductivity induced by the presence of the gas is measured The duration of asingle measurementis too shortto geta reliable measure successive measurements are made which induce each time aconductivity curve The average slope of each measurement curve determines the average conductivity which gives the gas concentration of the sample To perform the successive measurements it is necessary to purge the gas enclosed in the micro volume every 10 seconds This purge is done by injecting a purge gas which is different fromthe sample to be measured for instance N2 for a CO2 measurement A purge valve controlled by an electronic card drives this process After each purge the gas to be measured diffuses again through the membrane into the sensor and a new measurement is performed Dextens SA m 18 Chemin des Aulx m 1218 Pla

Operating Manual Dextens Thermo Conductivity Sensors

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