- Precision resistance standards designed for use up to 10 kHz
- Available for values from 1 mΩ - 10 MΩ
- Bnc option available (add -bnc to end of part number)
- Contact IET for custom resistance values
- Very stable <20 ppm/year for most values at ac and dc
- ISO-17025 accredited calibration at dc and 1 kHz Included
- < 25 ppm difference between dc / 1 kHz for resistances ≤ 100 kΩ
- Excellent temperature coefficient, as low as 1 ppm/°C
Most precision standard resistors are sealed. Where sealed resistors are more stable, they have a poor frequency response. IET has designed and manufactured our SRAC Series which has excellent ac frequency response while maintaining long term stability of less than 20 ppm.
Calibration: Unlike most resistors, where the calibration value is only available at dc, IET Labs provides an ISO-17025 accredited calibration of these resistors at dc and at 1 kHz. Sweep calibrations and other frequencies are available for a premium.
Configuration: Units come standard with 4 gold plated low thermal emf binding posts, plus ground for use in both 2, 3 or 4-Wire kelvin applications. For a small premium we can make this in any configuration you require including bnc.
Decade Box: If you are looking for a Decade Resistor with very strong ac performance consider our 1433 Series
Frequency response lower resistance, for example, 1 Ω will have a much better frequency response than higher resistance, for example, 10 MΩ
Because calibration uncertainties are much better at dc than ac, IET recommends that for resistance values below 1 MΩ it is recommended to use the dc value for the ac value at 1 kHz. For resistance values of 1 MΩ and 10 MΩ it is recommended to use the ac value.
The frequency response for SRAC values of 100 kΩ and lower is based upon the formula below;
|Model SRac-||Nominal (Ω)||Initial adjustment to nominal (ppm)||Stability 1 year (ppm)||Tempco (ppm/°C)||Resistor Type||Calibration uncertainty dc (ppm) (typical)||dc to ac change at 1 kHz (ppm) (Typical)||Max Power (W)||Max Voltage (V)||Max Current (A)||Terminals|
|0.001||0.001||200||50||20||Manganin strip||200||25||0.2||0.015||14||4 bp's + gnd|
|1K||1 k||1||5||77.5||7.7 mA|
|10K||10 k||1||2||245||2.5 mA|
|100K||100 k||1||2||300||2 mA|
|1M||1 M||5||Wirewound||5||250||0.5||700||0.7 mA|
|10M||10 M||15||Film||10||2500||0.1||1000||0.1 mA|