6.0 Calibration Procedures
The 3M™ Wrist Strap Tester 746 cannot be adjusted, but the following steps can be used to determine that the tester is operating within its specification.
Equipment needed:
1.Resistance Substitution Box
(750 kΩ - 11 MΩ, tolerance < 2%)
2.2 leads (to connect the resistance box)
Wrist strap test circuit check:
Connect the resistance substitution box to the 746 as shown in figure 2.
Set the resistance substitution box to each value of resistance indicated in the test table and press contact plate A.
The LEDs will indicate as shown below if the unit is functioning within specifications.
Resistance | Resistance | LED | |
substitution box | range of | ||
indication | |||
settings | the 746 | ||
| |||
|
|
| |
*750 kΩ | 750 kΩ | red | |
900 kΩ | green | ||
| |||
|
|
| |
9.0 MΩ | 10 MΩ | green | |
11.0 MΩ | red | ||
|
*This example is used in figure 2.
| 746 |
|
700 k | wrist strap tester |
|
|
| |
900 k | o.k. | o.k. |
9.0 M |
|
|
11.0 M | A |
|
|
| |
Resistance substitution box |
|
|
| Crocodile clip | |
figure 2
5 |