SR104 PRIMARY RESISTANCE STANDARD

SR104 Primary Resistance Standard is a highly stable and accurate (1ppm), 100000 ohm, resistance standard.
SR104 Resistance Standards are equipped for five-terminal measurements used for Standard Resistor readings and for Temperature Sensor readings. Calibration data, which identifies the Standard Deviation, and the Temperature Characteristics is supplied with each unit. In addition, each unit is equipped with a thermal well so that the exact temperature of the resistance standard is known.
This allows the user to make highly precise, temperature compensated, measurements.

• Highest accuracy and stability.

• Lowest temperature coefficients.

• Stability ±1 ppm/year the first 2 years; ±0.5ppm/year thereafter

• Initial Value SR104, SR104/DC ±1 ppm

Temperature Coefficient

Alpha (temperature coefficient) less than ±0.1 ppm/ºC at 23 ºC. Beta (1/2 rate of change of temperature coefficient) does not exceed 0.03 ppm/ºC2 over the temperature range of 18 ºC to 28 ºC. This performance is as a passive device without ovens or external power requirements.

Internal Temperature Sensor

The internal temperature sensor is a 1,000 ppm/ºC RTD with integral thermowell provided for calibration.

Termination

Five-terminal construction, four-terminal resistor with ground intercept for the standard and temperature sensor. The four resistor binding posts are gold plated tellurium copper to reduce thermal emf.
The ground terminals are brass.

Thermal emf

Under normal conditions thermal emf at the terminals does not exceed ±0.1 μV.