6
3M
™
Dual Conductor
Remote Input Jack
733 (optional)
Figure 1 – 3M
™
Workstation Monitor 724 with remote input jacks.
3M
™
Dual Conductor
Remote Input Jack
732
3M
™
Workstation
Monitor 724
SECTION 1
Theory of Operation
The 3M
™
Workstation Monitor 724 (Figure 1) is designed to monitor the
operation of the wrist strap grounding systems of two operators. To accomplish
this, it uses a DC current source to measure a loop electrical resistance. The
system uses a special wrist band and ground cord that contain two independent
elements. The Workstation Monitor 724 employs two selectable test voltages
(9 and 16 volts) and resistance limits (10 Megohms and 35 Megohms). It
also monitors the grounding of up to two 3M work surfaces. The Workstation
Monitor 724 contains a current-limiting resistor, through one side of the wrist
band, through the skin of the wearer under the band, through the second side of
the wrist band, through the second conductor of the ground cord that contains a
current-limiting resistor, and finally back to the monitor.
Note: There is no power switch or LED power indication light. LED lights will illuminate, verifying
power is on, once a wrist strap cord has been inserted.
Selection of Test Voltage and Resistance Limit
