3M 745 - Page 6

Verification Procedure
The 745 wrist strap tester cannot be calibrated, but the following steps can be used
to determine that the 745 is operating within its specification.
Equipment needed
Le resistance substitution box — 750 k - 11 Megohms, accuracy < 2%
2: 2 wires - as required to connect the resistance box to the 740
Check of wrist strap test circuit
Connect the resistance substitution box to the 745 as shown in figure 2.
Adjust the resistance substitution box to each value of resistance indicated in test table
and press contact plate A.
The lamps will indicate as shown below, if the 745 is functioning within specifications.
resistance resistance range | LED indication
substitution box | of the 745
setting
* 750 k Ohms 750 k Ohms red
900 k Ohms green
9.0 M Ohms 10 M Ohms range green
11.0 M Ohms red
* This example is used in figure 2