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Interpreting the Display
All Valhalla ohmmeters and igniter testers use a high impedance voltmeter as part of the resistance
measurement process. This voltmeter is a highly accurate and stable 24 bit analog-to-digital converter
(ADC). Unless it is receiving a definite input signal, the output reading of this ADC is ambiguous. The display
may indicate a randomly wandering number or it may indicate an over-range condition. This unpredictable
display may make it seem to appear that the instrument is experiencing some sort of malfunction. It is, in
fact, just a characteristic of the voltmeter circuit and should not be mistaken for a fault in the instrument.
The display indications should be ignored unless there is a definite measurement being taken. If this
wandering display is not acceptable, the ohmmeter can be made to indicate zero whenever the sense
terminals are shorted.
The display should indicate a stable reading when the test leads are securely attached to the device under
test. If the display appears to be erroneous when connected to a load, recheck the test leads for integrity
and cleanliness. If all external items appear to be functioning properly, the problem may be the
ohmmeter. In this case, please contact your local Valhalla Scientific Sales Office.
Fail-Safe Operation
The 4314Ki incorporate a proprietary current source design that renders them incapable of delivering
excessive voltage or current to the device under test. Maximum Fail-Safe Current values are list in Table
3.
Range
Fail-Safe Current
2Ω
< 8mA
20Ω
< 8mA
200Ω
< 1.8mA
2kΩ
< 180µA
20kΩ
< 18µA
200kΩ
< 1.8µA
2MΩ
< 180nA
20MΩ
< 18nA
Table 3 - Fail-Safe Current Values per Range
Every 4314Ki Igniter Testers are thoroughly tested before the leaves the factory. This includes a failsafe
test that simulates a "worst case" failure condition. The resulting output current is recorded and provided
on the Certificate of Calibration included with every unit.
