- New Design, with improved specifications
- Versatile working calibration resistor
- Laboratory standard of high accuracy and stability
- Adjusted to within 20 ppm of nominal
- 50 ppm long-term accuracy for most values
NEW DESIGN, IMPROVED SPECIFICATIONS
For a wider range of resistance values with similar performance at the same price consider our SRX Series
The Model SR1 Calibration Resistors is a laboratory standard of high accuracy and stability. The resistance of most values is initially adjusted to an accuracy of 20 ppm of nominal, with long-term accuracy guaranteed to better than 50 ppm. Other values have initial accuracy from 50 ppm to 200 ppm.
Model SR1 Calibration Resistor has been constructed to meet today’s high standards of performance. The resistance wire used is a modern alloy with excellent stability, an extremely low temperature coefficient over a wide range of temperatures, and very low thermal EMF to copper. Hermetically sealed wire wound resistors are used for most values. The durable aluminum case provides electrostatic shielding. Gold plated terminals reduce connection errors.
esi SR1 housing (option)Manufactured using the same housing as the original esi SR1. Terminals appear on the top of each unit. They are also brought out the bottom of the case on removable banana plugs. This allows plugging two or more units together in either series or parallel for a wide variety of resistance values. Four-terminal resistance measurements are easily made by using the banana plugs on the bottom of the case as two of the terminals. 0.01 Ω and 0.1 Ω values have four terminals on the top and should only be used in four-wire configurations. For three-terminal or five-terminal guarded measurements, a binding post on top and a banana plug on the bottom provide connections to the case.
SPECIFICATIONS
Nominal Value | Model Number | Adjustment to nominal | Stability per year | Temperature | Power | Max. power | Max. current | Max. voltage | Terminals |
0.01 Ω | SR1-0.01 | 200 ppm | 50 ppm | 20 ppm/°C | 0.1 ppm/mW | 2 W | 14 A | 0.15 V | 4 bp's + gnd |
0.1 Ω | SR1-0.1 | 200 ppm | 50 ppm | 20 ppm/°C | 0.1 ppm/mW | 1 W | 3.0 A | 0.3 V | 4 bp's + gnd |
1 Ω | SR1-1 | 20 ppm | 20 ppm | 10 ppm/°C | 0.5 ppm/mW | 0.25 W | 0.5 A | 0.5 V | 4 bp's + gnd |
10 Ω | SR1-10 | 10 ppm | 10 ppm | 3 ppm/°C | 0.15 ppm/mW | 0.1 W | 0.1 A | 1 V | 4 bp's + gnd |
100 Ω | SR1-100 | 10 ppm | 10 ppm | 1 ppm/°C | 0.05 ppm/mW | 0.1 W | 30 mA | 3 V | 4 bp's + gnd |
1 kΩ | SR1-1k | 10 ppm | 10 ppm | 1 ppm/°C | 0.05 ppm/mW | 0.1 W | 10 mA | 10 V | 4 bp's + gnd |
10 kΩ | SR1-10k | 10 ppm | 10 ppm | 1 ppm/°C | 0.05 ppm/mW | 0.1 W | 3 mA | 30 V | 4 bp's + gnd |
100 kΩ | SR1-100k | 10 ppm | 10 ppm | 1 ppm/°C | 0.05 ppm/mW | 0.1 W | 1 mA | 100 V | 4 bp's + gnd |
1 MΩ | SR1-1M | 20 ppm | 15 ppm | 3 ppm/°C | 0.15 ppm/mW | 0.1 W | 0.3 mA | 316 V | 2 bp's + gnd |
10 MΩ | SR1-10M | 20 ppm | 20 ppm | 5 ppm/°C | 0.25 ppm/mW | 0.1 W | 0.1 mA | 2000 V | 2 bp's + gnd |
* Max. power is specified for no change in resistance value beyond stated stability. See ** Power Coefficient note for maximum rated power.
**Power Coefficient: Resistances of 1 Ω and higher use hermetically sealed wirewound resistors that have a maximum rated power of 1.0 W. Operation at values higher than 0.1 W will cause selfheating effects on the order of 50 °C/W, assuming a 23°C ambient temperature. This will cause a reversible change in resistance beyond stated stability.
Calibration conditions:
At 23°C, low power, traceable to SI
< 1 MΩ: Five-wire
> 1 MΩ: Three-wire
Terminals:
Gold-plated, tellurium-copper, low-thermal-emf binding posts on standard 3/4 inch spacing.
Mechanical information:
Dimensions:
10.2 cm W x 8.9 cm H x 14.0 cm (4.0" W x 3.5" H x 5.5" D)
Weight: 0.9 kg (2 lbs)
