Summary of Contents for World Precision Instruments EVOM2
- Page 1 WORLD PRECISION INSTRUMENTS Instrumenting scientific ideas INSTRUCTION MANUAL EVOM2 Epithelial Voltohmmeter Serial No._____________________ www.wpiinc.com 082318...
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Page 3: Table Of Contents
APPENDIX C: IMPROVING THE ACCURACY AND REPEATABILITY OF THE SYSTEM ..20 Copyright © 2018 by World Precision Instruments. All rights reserved. No part of this publication may be reproduced or translated into any language, in any form, without prior written permission of World... - Page 4 DECLARATION OF CONFORMITY ....................22 WARRANTY .............................23 Claims and Returns ........................23...
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Page 5: About This Manual
Resistance (TEER) measurement in tissue culture research. EVOM2 is the next generation. The confluence of the cellular monolayer is determined by an increase in TEER detected using the unique electronic circuit of the EVOM2 and STX2 electrode (included with the instrument). The EVOM2 qualitatively measures cell monolayer health and quantitatively measures cell confluence. -
Page 6: Quick Reference
Sterilize the electrode. Connect the electrodes to the EVOM2 and leave the power off. Equilibrate the electrode in growth media with the EVOM2 power off and the Function switch set to Ohms. NOTE: Electrode tips must be immersed in solution to equilibrate. -
Page 7: Unpacking
Ag/AgCl pellet voltage sensors. They are referred to as voltage electrodes. Fig. 3–(Right) STX2 electrode Meter The EVOM2 is ready to use, but you will need a slot-head screwdriver (not included) to calibrate the R ADJ screw. WORLD PRECISION INSTRUMENTS... - Page 8 Charger Input Jack: Insert the charger connector into the Charger Jack and plug the other end into a standard wall outlet to charge the EVOM2 battery pack. Do NOT take resistance or voltage measurement with the charger connected. WORLD PRECISION INSTRUMENTS...
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Page 9: Instrument Diagnostics
Set the Function Switch to Ohms. Disconnect the EVOM2 from the charger and turn the Power on (I). The meter should display 1000W. If not, adjust the R ADJ screw with a small slot-head screw- driver until the meter shows a reading of 1000W. - Page 10 Check the tip of the electrode, and repeat this procedure until the electrode is the proper length. Fig. 9–(Right) Sanding STX2 electrode WORLD PRECISION INSTRUMENTS...
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Page 11: Making Resistance Measurements
Making Resistance Measurements When the EVOM2 is used for resistance measurements only, the electrode does not need to be equilibrated or preconditioned before use. Any galvanic voltage asymmetry present on the measurement electrode is cancelled by the EVOM2 circuitry. -
Page 12: Maintenance
100mM KCl for 12–24 hours while the electrode is connected to the EVOM2. Set the Function switch to Ohms, and power off the meter. After equilibration, set the Function switch to Millivolts. Then, turn the meter on again and repeat step 5. -
Page 13: Disinfecting The Stx Electrode
(ETO). CAUTION: Do NOT autoclave the electrode. CAUTION: Do NOT expose the electrodes to ultra-violet light, because UV light decomposes silver/silver chloride electrodes. WORLD PRECISION INSTRUMENTS... -
Page 14: Resurfacing The Electrode
Short term storage (overnight): Immerse the electrode tip in electrolyte solution. Ensure the electrode cable plug is connected to the electrode port on the EVOM2 meter and the meter is turned off, so that the system is short-circuited. This serves to maintain electrochemical symmetry. -
Page 15: Changing The Battery Pack
EVOM2, replacements are available (WPI #91736). See "ACCESSORIES" on page 13. To change the battery pack: Using a #1 Phillips screwdriver, remove the four screws from the EVOM2 case. The battery pack is mounted on the bottom chassis plate. Using a #1 Phillips screwdriver, remove the two screws securing the battery pack cover. - Page 16 Re-secure the battery pack cover with the two Phillips screws. CAUTION: Before you reassemble the case, verify that no bare wires touch the metal chassis. Reassemble the EVOM2 case. Charge the new battery pack for at least 24 hours. WORLD PRECISION INSTRUMENTS...
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Page 17: Accessories
1mm in thickness. Each probe has an outer (voltage) and an inner (current) electrode. STX3 is an alternative electrode to the STX2 that can be used with the EVOM2. It differs from the STX2 in that the vertical distance between the probes of the STX3 can be adjusted. -
Page 18: Troubleshooting
Endohms are is an optional electrode chambers for the EVOM2 that may be used when working with well cups that are individually removable. It can also be used for studying the tight junction changes induced by chemicals and other factors. - Page 19 Possible Cause Solution Unit is insuffi- Recharge the unit for at least 12 hours. ciently charged NOTE: Make sure the EVOM2 is powered off when charging the battery. Insecure con- Verify that the power connector is securely connected nection at power at the meter power input jack.
- Page 20 Use the test resistor to verify the meter is functioning correctly. The meter display should read 1000W. Refer to the appro- priate electrode manual for instructions on testing the electrode. WORLD PRECISION INSTRUMENTS...
- Page 21 1- 2 years with normal use. NOTE: If you have a problem/issue with your EVOM2 that falls outside the definitions of this troubleshooting section, contact the WPI Technical Support team at 941.371.1003 or technicalsupport@wpiinc.com.
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Page 22: Specifications
* When the battery power level falls below a minimum threshold, the unit automatically powers off. A fully-charged battery will provide about eight hours of running time. Make sure the EVOM2 is powered off when charging the battery. APPENDIX A: RESISTANCE CALCULATIONS... -
Page 23: Resistance Value Of The "Blank" Insert
EVOM2 Resistance Value of the “Blank” Insert When using an EVOM2 with an STX2 to measure a blank insert, the resistance value is typically between 120 to 180W, depending on the specific brand of the insert. This is not background resistance due to the resistance of the blank filter. Rather, if the filter... -
Page 24: Appendix B: 24 Mm Diameter (6-Well) Inserts And Stx Electrodes
This is not a problem with smaller inserts, such as the 12mm and 6mm diameter inserts, because of the relatively smaller size of the membrane compared to the electrode. When EVOM2 is used with the Endohm, it gives a repeatable and accurate value of membrane resistance consistent with that obtained by using a well-designed Ussing chamber. - Page 25 15 shows how the Endohm chamber measures TEER. With fixed electrode geometry, the variation of readings on the same sample is 1-2W as compared to 5-10% of the total reading using the STX2 electrodes. The Endohm, together with the EVOM2, offers the most accurate, convenient and economical solution for trans membrane electrical resistance measurement.
- Page 26 DECLARATION OF CONFORMITY WORLD PRECISION INSTRUMENTS...
- Page 27 EVOM2 WARRANTY WPI (World Precision Instruments, Inc.) warrants to the original purchaser that this equipment, including its components and parts, shall be free from defects in material and workmanship for a period of one year* from the date of receipt. WPI’s obligation under this warranty shall be limited to repair or replacement, at WPI’s option, of the equipment or defective components or parts upon receipt thereof f.o.b.
- Page 28 International Trade Center, 175 Sarasota Center Blvd., Sarasota FL 34240-9258 Tel: 941-371-1003 • Fax: 941-377-5428 • E-mail: sales@wpiinc.com 1 Hunting Gate, Hitchin, Hertfordshire SG4 0TJ Tel: 44 (0)1462 424700 • Fax: 44 (0)1462 424701 • E-mail: wpiuk@wpi-europe.com Germany Saarstraße 23, D-61169 Friedberg (Hesson), Germany Tel: +49 (0)6031 1602171 •...
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