5
Caution
The Model 725 Monitor does not have
the capability of verifying that the
ground point is a suitable ground. If
you are not sure what a suitable ground
is, contact a licensed electrician before
installation.
The Model 725 Monitor requires only
a small amount of current to operate.
When the red lamp and the audible
alarm are activated simultaneously the
monitor requires approximately 5 µA
of current. When the lamp and alarm
are not activated (normal condition)
the monitor requires approximately
50
µ
A of current.
As with any battery operated electronic
device, the life of the battery will be
determined by the frequency of use.
However, for the Model 725 Monitor
you can expect a battery life of
approximately one year in continuous
operation under normal conditions.
Note:
Use an alkaline battery for longer life.
The Model 725 monitors the battery
voltage and alerts the operator when it
is necessary to change the battery.
When the battery voltage falls below
6 volts the red lamp will illuminate
with no audible alarm. At this time the
Model 725 is still operational, making
reliable resistance measurements
of the wrist strap assembly and the
ground connection.
Voltage on Operator when Connected
to the Model 725 Monitor
There is a concern about the voltage
that is applied to an operator while
they are connected to a monitor.
Some of today’s electronic
components are extremely sensitive
to electrostatic discharge from a person
(less than 10 volts). The following
chart for the Model 725 Monitor
illustrates the level of voltage that will
appear on the operator under various
resistance conditions.
Voltage on Operator When Connected to the Model 725 Monitor
Condition
Observed Voltage
No Skin Resistance
0.8V
200K Ohm Skin Resistance
0.9V
Likely Case Before Alarm
3.5V
Worst Case Before Alarm
6.8V
Absolute Worst Case
9.0V
