720A Kelvin-Varley Divider
Key features
- High-resolution primary standard for ratio measurements
- 0.1 ppm of input absolute linearity, 0.1 ppm resolution, seven decades
- Temperature coefficient of linearity of 0.1 ppm/ºC
- Built-in self-calibration bridge
Product overview: 720A Kelvin-Varley Divider
A primary standard for ratio measurements
Model 720A Kelvin-Varley Divider is a high-resolution primary ratio standard with absolute linearity of 0.1 ppm, temperature coefficient of linearity of 0.1 ppm/ºC, and self-calibration capability.
- 0.1 ppm resolution, seven decades
- 0.1 ppm of input absolute linearity
- Built-in self calibration bridge
- Front panel self-calibration
Specifications: 720A Kelvin-Varley Divider
| General specifications | |
| Ratio range | 0 to 1.0 (1.0 input tap) and 0 to 1.1 (1.1 input tap) |
| Resolution | 0.1 ppm of input with seven decades 0.2 |
| Absolute linearity | (At calibration temperature and without the use of a correct chart) ±1.0 ppm of input at dial settings of 1.1 to 0.1, ±0.1 (10S)1/3 of input at dial settings (S) of 0.1 to 0 |
| Absolute linearity stability | (Without self-calibration) ±1.0 ppm of input/yr at dial settings of 1.1 to 0.1, ±1.0 (10S)(2/3) ppm of input/yr at dial setting (S) of 0.1 to 0 Note: Absolute linearity is defined as the linearity between max and min output voltages. The self-calibration procedure may be used at any time to reset absolute linearity to ±0.1 ppm of input. |
| Temperature coefficient of linearity | ±0.05 ppm of input ºC maximum at dial settings of 1.1 to 0.1 |
| Short-term linearity stability | Under typical standards laboratory conditions (temperature maintained within ± 1 ºC) and with an applied voltage of up to 100V, stability of linearity is ± 0.01 ppm/24 hours and ± 0.1 ppm/30 days |
| Power coefficient of linearity | ±0.2 ppm of input/W max at dial settings of 1.1 to 0.1; ±0.2 (10S) 2 ppm of input/W max at dial settings (S) of 0.1 to 0 |
| Maximum end errors | Zero error at output low: 0.004 ppm of input Zero error at input low: 0.05 ppm of input Full-scale error: 0.05 ppm of input |
| Maximum input voltage | 1000 V on 1.0 input terminal, 1100 V on 1.1 input terminal |
| Thermal voltages | ±0.5 μV max |
| Input resistance | 100 kΩ ±0.005% at 1.0 input terminal at 25 °C, 110 kΩ ±0.005% at 1.1 input terminal at 25 °C |
| Temperature coefficient of input resistance | ±1 ppm per °C max |
| Size | 14 cm H x 48.2 cm W x 33 cm D, rack mounted (5.5 in H x 19 in W x 13 in D) |
| Weight | 8.15 kg (18 lb) |
Models: 720A Kelvin-Varley Divider
720A
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