RS925D Decade Resistance Standard.
RS925D Decade Resistance Standard is a four-terminal,
continuously variable resistance standard. Values from 10mΩ to 1.2MΩ can be achieved using eight decade
switches.
The rheostat offers a resolution of 20mΩ. Use of Evanohm, wire-wound precision resistors provide an
accurate, stable standard with good temperature characteristics.
The Model RS925D can be used as a standalone resistance standard or in conjunction with the
Models 801B/801C, and 240C to complete a 242D or 242E Resistance Measurement System.
RS925D Decade Resistance Standard.
| Model | Description |
|---|---|
| RS925D | RS925D Decade Resistance Standard. |
High accuracy - 20 ppm + 0.5 mΩ
High stability - 20 ppm + 0.5 mΩ
Resistance from 10 mΩ to 1.1 MΩ
20 µΩ resolution
20 µΩ resolution In order to eliminate contact resistance and thermal emf, the RS925D integrates a
rheostat. As a result, voltage and contact resistance effects are removed by being effectively added to
the input impedance of the measuring instrument.
Low temperature coefficient - as low as 3 ppm/°C.
High performance solid silver contact switches
Hermetically sealed, low inductance resistors.
Precise fixed minimum resistance.
The first 4 decades can be individually trimmed for increase accuracy.
| Resistance per step | Total decade resistance | Max current | Max power | Temperature coefficient(ppm/C) |
Power coefficient(ppm/mW) |
|---|---|---|---|---|---|
| 20 µΩ Rheostat | 10 mΩ | 2A | NA | 20 | 1 |
| 10 mΩ | 100 mΩ | 2A | NA | 20 | 1 |
| 100 mΩ | 1 Ω | 2A | NA | 20 | 1 |
| 1 Ω | 10 Ω | 1A | 5 W | 20 | 0.4 |
| 10 Ω | 100 Ω | 0.33 A | 5 W | 10 | 0.3 |
| 100 Ω | 1 kΩ | 0.1 A | 5 W | 3 | 0.1 |
| 1 kΩ | 10 kΩ | 33 mA | 5 W | 3 | 0.1 |
| 10 kΩ | 100 kΩ | 10 mA | 5 W | 3 | 0.1 |
| 100 kΩ | 1 MΩ | 3 mA | 2000 V peak |
3 | 0.1 |
| Wiring and switch resistance |
NA | 50 μΩ/C | 0.2 μΩ/W | NA |