Lake Shore Model 420 Gaussmeter User’s Manual
Installation
2-3
2.4 INITIAL SETUP AND SYSTEM CHECKOUT PROCEDURE
This procedure verifies basic unit operation before initial use for measurements.
CAUTION: Check power source for proper voltage before connecting line cord. Check power
setting on fuse drawer window. Damage may occur if connected to improper voltage.
1.
Check power source for proper voltage. The Model 420 operates with 100, 120, 220, or 240
(+5%, –10%) AC input voltage.
2.
Check fuse drawer window for proper voltage setting. If incorrect, see Paragraph 5.2.
3.
Ensure power switch is off (O).
CAUTION: The probe must be connected to the rear of the unit before applying power to the
gaussmeter. Damage to the probe may occur if connected with power on.
4.
Plug in the DA-15 probe connector to PROBE INPUT. Use thumbscrews to tighten connector to unit.
5.
Connect and check all other rear panel connections (SERIAL I/O, or ANALOG OUTPUTS) before
applying power to the unit.
6.
Plug line cord into receptacle.
7.
Turn power switch on (I). The front panel display turns
on and briefly displays the message to the right.
8.
The normal gaussmeter display appears, similar to the
one to the right.
NOTE:
For best results, warm up instrument and probe
for at least 5 minutes before zeroing probe, and at least
30 minutes for rated accuracy. The probe and the zero gauss chamber should be at the same
temperature.
Some Lake Shore probes come with a clear plastic sleeve to protect the probe tip when not in use. The
sleeve slides up and down the probe cable. To place the probe in the zero gauss chamber, slide the
protective sleeve back, exposing the probe tip, before placing the tip in the chamber.
9.
Place the probe in the zero gauss chamber and press
the front panel
Zero Probe
key. The display to the right
appears.
10.
Press
Zero Probe
again. The *CALIBRATING* message briefly displays, followed by the normal display.
Do not move the probe while the *CALIBRATING* message displays.
NOTE:
If the unit performs well to this point, the unit is functioning properly. If there is a reference magnet
available, continue the test using the magnet to verify the Model 420 accuracy.
11.
If continuing the procedure with a reference magnet, verify the probe accommodates the magnet range.
Use the
Range Select
key to select the proper range (or press
Auto Range
). Set the display for DC.
Finally, since probe orientation is very selective, press
Max Hold
to capture the highest reading.
CAUTION: Take care when handling the probe; its tip is very fragile. Excess force may break it.
NOTE:
Probe readings depend on the angle of the tip in relation to the magnetic field. The greater the
angle, the higher the percentage of error. For example, a 5° angle causes a 0.4% error, a 10° angle
induces a 1.5% error, etc. See Paragraph 3.15.
12.
Carefully place probe in contact with the magnet and
hunt a bit for the maximum reading. For this example,
we used a 999 ±1% Gauss probe reference magnet.
The top line displays the current reading. The bottom
line displays the maximum reading captured, which is
within the tolerance of our reference magnet. The top line continually changes as the probe moves, but
the bottom remains fixed on the highest reading. To capture a new maximum value, press
Max Reset
.
After successfully completing this checkout procedure, the unit is ready for normal operation.
L a k e S h o r e 4 2 0
F ie ld M o n it o r
0 .0 0
k G
+
D C
P r e s s A g a in W it h
P r o b e A t Z e r o
k G
0 .9 9 5
0 .9 7 2
M A X
k G
+
D C
Summary of Contents for 420
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