TB-9031
Page 3 of 4
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SCS
- 926 JR Industrial Drive, Sanford, NC 27332 • (919) 718-0000 • Website:
StaticControl.com
Dissipative (Soft) Grounds
This test verifies proper operation of soft (dissipative)
ground monitoring such as of mats.
Setup – Ground Resistance
Setup switches to allow you to set the parameters in
accordance with your specification. Dissipative ground
resistance setting is done using switches 1-4.
All other switch positions are unused for this purpose.
Pressing “Soft Ground” push-button switch will result
in load with slightly lower resistance than the alarm
threshold.
Procedure
When measuring dissipative grounds, there could be up
to a 30 second delay before the alarm is triggered. This
eliminates any false alarms due to temporary noise.
• Plug banana end of red cable of the Workstation
Monitor Checker into the Ground Under Test jack of the
Workstation Monitor Checker.
• Plug the thin tip of red cable into soft ground terminal of
your monitor. Make sure that the contact is good.
• Ground monitor shall indicate failure (typically, red light
on the monitor). A momentary “blink” of pass light on the
monitor (typically green) when the button is pressed is
acceptable.
• Press “Soft Ground” button on your Workstation Monitor
Checker. Ground monitor shall indicate good ground
(typically green light). Allow up to 30 seconds for alarm
to trigger for some monitors.
• After release of “Soft Ground” button the ground monitor
shall indicate failure. Allow up to 30 seconds for alarm
to trigger for some monitors.
Wrist Strap
The Workstation Monitor Checker verifies proper
operation of dual conductor wrist strap monitors.
Setup
The Workstation Monitor Checker provides resistance
of a certain value across the wrist strap terminal input
in order to simulate a wrist strap. A good quality dual
wrist strap has a 1 megohm resistor in each half.
The Workstation Monitor Checker is designed to test
cords with and without resistors. The default is set to
no resistor. A dip switch will configure the Checker to
be used with a 1 megohm resistor cord. (2 megohms
resistance in series.)
Procedure
• Connect 3.5 mm test cable to both the
Workstation
Monitor Checker and to the Operator jack of your
monitor. At this point the monitor should indicate
failure.
• Press the “Wrist strap” button. Your monitor LED will
turn from red to green and your audible-alarm will turn
off.
Body Voltage
For monitors capable of measuring body voltage, first
set the body voltage threshold by pressing the Body
Voltage button and turning the blue potentiometer while
measuring the voltage to ground on the tip of the 3.5 mm
plug. Red and green LEDs alternatively blink indicating
either positive and negative voltage.
The voltage applied directly to the terminal of the monitor
is 1/2 of the voltage on the operator due to 1 megohm
resistors in the wrist strap. Set Body Voltage on the
Workstation Monitor Checker slightly higher than your
monitor. Monitors are calibrated to 2.5V body voltage.
Press the Wrist strap and Body Voltage High buttons
simultaneously and set your Workstation Monitor
Checker to 1.35V which is slightly higher than 1/2 of
2.5V. Your Workstation Monitor Checker can be set up to
5V.
Switch Position
Monitor Alarm Threshold 1
2
3
4
1000 megohms
0
0
0
1
400 megohms
0
0
1
1
100 megohms
0
1
1
1
10 megohms
1
1
1
1
Figure 4. Metal ground contact on the CTC065 Ground
Master Monitor. Do not use screw as contact point.
Resistance (megohms)
Switch Position 10
12
0
10
1