Datasheet

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A GREATER MEASURE OF CONFIDENCE
Offset Compensation — Voltage Limit/Dry Circuit Ohms — Temperature Measurements
SWITCH/MEASURE SYSTEMS
15
Integra Series Multimeter/Switch Systems
Offset Compensation
For more accurate low resistance measurements, all Integra systems provide the offset compensation
mode to eliminate errors from the thermoelectric EMF effects (V
EMF
). During the measurement cycle, the
built-in ohms current source is turned off, then turned on again, and the resulting EMF error is automati-
cally subtracted. This technique is typically used when measuring values less than 100Ω using the four-
wire ohms method.
Voltage Limit/Dry Circuit Ohms (Model 2750 only)
The use of dry circuit mode, when selected, limits the open-circuit voltage to 20mV. This allows resistance
measurements to be made with low power. When measuring contact and connector resistances, it is
important not to puncture oxides and films that may have formed. Standard resistance measurements
have open-circuit voltage levels from 5.4V to 12.8V, depending on the selected range.
Dry circuit ohms can be used on the 1Ω, 10Ω, 100Ω, and 1kΩ ranges for the four-wire ohms (Ω4) func-
tion. Also, offset compensated ohms (OCOMP) can be used with dry circuit ohms to cancel the effect of
thermoelectric EMFs.
Dry circuit ohms should be used for any device that could be damaged by high open-circuit voltage. If
not sure, and the slightly degraded accuracy is not a consideration, it is good practice to use dry circuit
ohms to measure low resistance.
The accuracy specifications for all dry circuit ohms ranges are with offset compensated ohms and line syn-
chronization enabled.
Temperature Measurements
The Integra systems support three major types of temperature sensors with built-in signal conditioning
and linearization: thermocouples, RTDs, and thermistors.
Thermocouples RTDs Thermistors
Temperature Range –200 ~ 1820°C –200 ~ 630°C –80 ~ 150°C
Advantage • Self-powered • High stability • Interchangeability
• Wide temperature • High accuracy • No CJC required
range • No CJC required • High accuracy over
limited temperature
range
Cost LowHigh Medium
The Integra systems provide built-in algorithms for a variety of thermocouples, RTDs, and thermistors. To
begin using a sensor, simply hook it up and the system does the rest.
• Thermocouples: Type J, K, N, T, E, R, S, B
•RTDs: D100, F100, PT100, PT385, PT3916, or user type
• Thermistors: 2250Ω, 5kΩ, and 10kΩ