Seaward DO5000 Series - Manual (Page 21)

Operating Instructions Microhmmeter Type DO5000
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For manual operation the Slow measurement mode should be selected. This will read at 2
measurements per second and offer the highest accuracy and resolution.
Press [Filt] to select the digital filter, this feature should be used when the sample to be
measured is unstable and the measured value displayed is constantly changing. The filter is a
rolling average of n measurements where n may be set between 1 and 32.
Press [Sett] to select the setting time filter; this would normally be used when measuring
inductive samples such as motor winding resistance.
Press [Limit] to set maximum number of permissible digits 1-999 that the reading can change.
Press [No of readings] to select the number of readings 2-999 that the set limit must conform
to.
4.4 Temperature Compensation
Press [Mode] to select the setup menu for temperature compensation
Press [Ext] to select the external temperature sensor.
Press [Man] to select the manual compensation temperature, the display will request that you
enter the ambient reference temperature.
Press [Cu] to select compensation for copper 3930 ppm/°C
Press [Al] to select compensation for Aluminum 4100 ppm/°C
Press [Usr] to enter alternative user coefficients
The equation used to calculate the corrected resistance is:
Rc (20°C) = Rx/1+ (tx - 20°C)
where Rc = resistance corrected for a reference temperature 20°C
} = Average temperature coefficient
tx = Component temperature at time of the measurement
The temperature compensation mode should be used when measurements are required to be
referenced to 20°C. This is particularly useful when measuring materials with a high
temperature coefficient such as copper, as the ambient temperature varies so will the
resistance value being measured. Using the temperature compensation mode references all
values back to a temperature of 20°C.
The compensated resistance value measured will be displayed in large digits in the centre of
the display and the true resistance will be displayed in smaller text below. The ohms sign of
the compensated value will show a 20 in the centre to indicate that the value is referenced to
20°C.