Revised August, 2004
10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110
•
5-2
MAINTENANCE
Oscilloscope: 20 MHz minimum bandwidth, 5 mV/div.
sensitivity. Tektronix Model 2205 or equivalent
Screwdrivers: Phillips No.2 and small flat-bladed
5.4
Performance Verification
WARNING
DO NOT TOUCH ANY ALLIGATOR CLIP WHILE THE TEST
PUSHBOTTUN IS PRESSED. LETHAL VOLTAGES MAY BE
PRESENT ON THESE CLIPS.
1.
Check the test voltages. Connect a DVM with at least 1
MΩ resistance between the ‘TEST’ (high) jack and the
‘SIG’ (low) binding post. Note that the OHMS RANGE
switch must be on the 1 MΩ range, or the short circuit
protection circuit may start to shut down the high voltage
power supply. Check that the voltages are as selected by
the ‘TEST VOLTAGE’ selector switch within ± 3%. If not,
there is no adjustment other than to check the various
components in the high voltage regulator circuit and to
replace any found to be defective.
2.
Check that the light-emitting diode circuit is operating
correctly. It should light when the ‘TEST’ pushbutton is
depressed (provided that the resistor under test is within
the selected resistance range) (Power must be ON).
3.
Check the accuracy of the resistance indication by
measuring resistors of known accuracy. Resistors
required are 50 kΩ, 1 MΩ, 10 MΩ, 100 MΩ, 1 GΩ, 10 GΩ,
and 100 GΩ. Check each range with a resistor of the
indicated value of that range and also with a resistor of
10% of that value, with the exception of the 1 MΩ range,
which should be checked with a 50 kΩ resistor. Check
first with 50 V and then with 500 V (but DO NOT CHECK
THE 50 kΩ AT 500 V). All readings must be within 5% of
the actual value. If not, adjust the trimpots as described
below.
