Service Information
5
-3
10 TEGAM WAY ● GENEVA, OHIO 44041 ● 440
-466-
6100 ● FAX 440
-466-
6110 ● [email protected]
5.2.2
Alignment Procedure
Preparation
CAUTION
Servicing and calibration must be done by qualified service personnel.
1.
This procedure shall be performed within environmental conditions of 23 ±
3
°C
and 5% to 95% RH.
2.
The unit under test (“UUT”) shall be acclimated to the controlled environment for a
minimum of four (4) hours.
3.
Remove the UUT battery door housing to expose the alignment access hole.
4.
Press
to turn the UUT on
.
5.
Leave the
720A
powered on for a minmum of ten
(10) minutes.
To disable Auto
-
Power Off, press
6.
Press
until unit is in 10 mΩ range.
7.
Short the leads of the unit in the following order: +I to
-
I,
-
I to +E, and +E to
-E.
(See
Figure 6
)
The unit should display 0.00
0
(
±0.002
)
.
8.
With the leads still shorted together, insert
a
rigid wire
through the alignment access hole
and gently press the calibration enable switch
located on the circuit board. See
for
location.
9.
The UUT display will indicate as follows:
a.
“1”
b.
Line 1:
-----
c.
Line 2:
10 m
Ω
10.
Press
for 2 sec to display stored value of short.
11.
Press
to select 0.000.
When using
to adjust the value displayed, the value will change slowly with
each keypress, but will accelerate if the key is held down.
Figure 6: Kelvin Clip Short
Orientation
If the unit displays ≈0.300 mΩ (±0.050), check that the connection of the shorted
leads are in the correct order
Figure 7: Alignment Access
Hole Location
