SCS TB-9117 Limit Comparator Instruction Manual
- June 17, 2024
- SCS
Table of Contents
SCS TB-9117 Limit Comparator Instruction Manual
Description
Frequency of re-calibration should be based on the critical nature of those ESD sensitive items handled and the risk of failure for the ESD protective equipment and materials. In general, SCS recommends that calibration be performed annually.
Use the SCS 770769 Limit Comparator to perform periodic verification (once every 6-12 months) of the SCS 770758 Dual Combination Tester. The Limit Comparator can be used to check the test limits of the Dual Combination Tester without removing it from the factory floor.
Packaging
- Limit Comparator
- Test Leads with Banana Plug Terminals, 5′ Length
Tester Configuration
The resistance limits for footwear and wrist strap tests are controlled by the DIP switches located on the sides of the tester. Use the following tables for the DIP switch settings and their corresponding test values.
FOOTWEAR RESISTANCE
DIP switches 1 and 2 control the HIGH test limit.
Figure 2. Locating the DIP switches on the Dual Combination Tester
| Switch 1 | Switch 2 | HIGH Limit Resistance |
|---|---|---|
| ON | ON | 10 Megohms (1 x 107) |
| OFF | OFF | 35 Megohms (3.5 x 107) |
| ON | OFF | 100 Megohms (1 x 108) |
| OFF | ON | 1 Gigohm (1 x 109) |
DIP switches 3 and 4 control the LOW test limit.
| Switch 3 | Switch 4 | LOW Limit Resistance |
|---|---|---|
| ON | OFF | 100 Kilohms (1 x 105) |
| OFF | ON | 750 Kilohms (7.5 x 105) |
default setting
WRIST STRAP RESISTANCE
DIP switches 5 and 6 control the HIGH test limit
| Switch 5 | Switch 6 | HIGH Limit Resistance |
|---|---|---|
| OFF | OFF | wrist strap test disabled |
| ON | ON | 10 Megohms (1 x 107) |
| ON | OFF | 35 Megohms (3.5 x 107) |
DIP switch 5 must be ON (default setting) for the wrist strap test to be active. The wrist strap test will be disabled if DIP switch 5 is set to OFF.
The LOW limit for the wrist strap test is set to 750 Kiloohms and cannot be modified by the user.
Operation
TESTING THE WRIST STRAP CIRCUIT
- Verify that the tester is connected to equipment ground.
- Plug the two included test leads into each yellow banana jack located at the top of the Limit Comparator.
- Connect one of the test leads from the Limit Comparator to the SINGLE-WIRE jack located on the face of the tester. Connect the other lead from the Limit Comparator to the ground jack located on the bottom of the tester.
- Select 750K LOW with the Limit Comparator’s rotary switch.
- Touch and hold the test switch on the tester until the results are displayed. The tester should indicate a wrist strap FAIL LOW condition.
- Select 750K PASS on the Limit Comparator and repeat the test. The tester should indicate a wrist strap PASS condition.
- Select either the 10M PASS or 35M PASS setting, whichever one is appropriate, on the Limit Comparator and repeat the test. The tester should indicate a wrist strap PASS condition.
- Select either the 10M HIGH or 35M HIGH setting, whichever one is appropriate, on the Limit Comparator and repeat the test. The tester should indicate a wrist strap FAIL HIGH condition.
TESTING THE FOOTWEAR CIRCUIT
- Insert the Limit Comparator’s stereo plug into the jack labeled FOOT PLATE on the bottom of thetester.
- Select the appropriate FAIL LOW setting on the Limit Comparator.
- Touch and hold the test switch on the tester until the results are displayed. The tester should indicate a FAIL LOW condition for both feet.
- Select the appropriate PASS LOW setting on the Limit Comparator and repeat the test. The tester should indicate a PASS condition for both feet.
- Select the appropriate PASS HIGH setting on the Limit Comparator and repeat the test. The tester should indicate a PASS condition for both feet.
- Select the appropriate FAIL HIGH setting on the Limit Comparator and repeat the test. The tester should indicate a FAIL HIGH condition for both feet.
CALIBRATING THE 1 GIGOHM FOOTWEAR LIMIT
Dual Combination Tester units with serial numbers ending in 2326001 or greater include firmware that allows field calibration of the 1 gig ohm footwear test limit when needed. Environmental conditions such as humidity and temperature may affect the test accuracy of the 1 gigohm limit. Should the Dual Combination Tester fail verification testing of the 1 gigohm test limit, use the following procedure to re-calibrate its parameters.
NOTE: Two 5-pound electrodes are required to complete this procedure. The
electrodes provide a method for loading the resistance from the Limit
Comparator onto each of the dual foot plate’s plates. One pair of 5-pound
electrodes are available as SCS item 770767.
Figure 3. SCS 770767 5-Pound Electrodes
-
Verify that the Dual Combination Tester is connected to power, equipment ground, and its dual foot plate.
-
Configure the DIP switch on the Dual Combination Tester as shown below.
-
Place one 5-pound electrode onto each plate on the dual foot plate.
-
Connect each electrode to the yellow banana jacks located at the top of the Limit Comparator using the two test leads.
-
Select 1G CAL with the Limit Comparator’s rotary switch.
-
Touch and hold the test switch on the tester until all six footwear LEDs rapdily blink and then remain illuminated. This confirms successful calibration of the 1 gigohm footwear test limit.
NOTE: An unsuccessful calibration is indicated if the six footwear LEDs do not rapidly blink. Verify the setup and confirm that all wires are properly connected. -
Reconfigure DIP switches 3-6 back to the desired footwear low and wrist strap high test limit settings.
-
Select 1G PASS with the Limit Comparator’s rotary switch.
-
Touch and hold the test switch on the tester until the results are displayed. The tester should indicate a PASS condition for both feet.
-
Select 1G HIGH with the Limit Comparator’s rotary switch.
-
Touch and hold the test switch on the tester until the results are displayed. The tester should indicate a FAIL HIGH condition for both feet.
Specifications
| Setting | Nominal Resistance | Nominal Resistance Tolerance |
|---|---|---|
| 100K LOW | 90 kΩ | ±2% |
| 100K PASS | 110 kΩ | ±2% |
| 750K LOW | 675 kΩ | ±2% |
| 750K PASS | 825 kΩ | ±2% |
| 1M LOW | 909 kΩ | ±2% |
| 1M PASS | 1.10 MΩ | ±2% |
| 10M PASS | 9.09 MΩ | ±5% |
| 10M HIGH | 11.09 MΩ | ±5% |
| 35M PASS | 31.09 MΩ | ±5% |
| 35M HIGH | 37.89 MΩ | ±5% |
| 100M PASS | 90.9 MΩ | ±5% |
| 100M HIGH | 112.9 MΩ | ±5% |
| 1G PASS | 812.9 MΩ | ±10% |
| 1G HIGH | 1.213 GΩ | ±10% |
| 1G CAL | 1.0 GΩ | ±5% |
These resistance values may be verified using a digital ohmmeter. Connect the ohmmeter’s test leads into each of the Limit Comparator’s yellow banana jacks. If any value is out of specification, the Limit Comparator must be returned to the manufacturer for repair.
| Operating Temperature | 50 to 95°F (10 to 35°C) |
|---|---|
| Environmental Requirements | Indoor use only at altitudes less than 6500 ft. (2 |
km)Maximum relative humidity of 80% up to 85°F (30°C)decreasing linearly to
50% @ 85°F (30°C)
Dimensions| 3.8″ L x 2.4″ W x 0.9″ H(97 mm x 61 mm x 23 mm)
Weight| 0.2 lbs (0.1 kg)
Country of Origin| United States of America
Limited Warranty, Warranty Exclusions, Limit of Liability and RMA Request
Instructions
Documents / Resources
| SCS
TB-9117 Limit
Comparator
[pdf] Instruction Manual
TB-9117 Limit Comparator, TB-9117, Limit Comparator, Comparator
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