9. Derating
Curve
The derating curve of the absolute maximum input voltage in common mode is shown as
follows.
10. Offset Adjustment
If the offset voltage is too large, short the input leads and turn the adjust variable resistor
(DC voltage adjustment) which you find in the hole of the panel by using a flat-head
screwdriver until the offset voltage is lowest.
11. Inspection Procedure
a. Connect the BNC output connector to the vertical input of a general purposed
oscilloscope.
b. Install four AA cells or connect an appropriate mains adaptor or power lead to the correct
line voltage.
c. Set the oscilloscope input coupling to DC and the 1V/div. Center the trace on the display.
d. Connect the inputs of the probe to power lines.
e. Set the range of the probe to 1/100.
f. Then, a 50Hz/60Hz sine-wave of proper amplitude will be displayed on the screen of the
oscilloscope and this means the probe is working properly.
12. Cleaning
Use a soft cloth to clean the dirt. Prevent damage to probe.
a. Avoid immersing the probe.
b. Avoid using abrasive cleaners.
c. Avoid using chemicals contains benzene or similar solvents.
