High accuracy and stability voltage dividers.
KVD 600 Kelvin Varley Voltage Divider.
KVD 700 Kelvin Varley Voltage Divider.
These standards grade Kelvin Varley voltage dividers are highly accurate, stable, and linear instruments for
use in many applications requiring accurately known voltage or current ratios.
In particular, the KVD series is especially appropriate for use in bridge circuits, providing two arms of a bridge
with a very well known ratio. Applications include linearity determination, the measurement of voltage and
resistance, and the calibration of voltage, current, and resistance.
Kelvin Varley Voltage Divider
| Model | Description |
|---|---|
| KVD-600 | Kelvin Varley Voltage Divider
|
| KVD-700 | Kelvin Varley Voltage Divider
|
Equivalent circuit: A Kelvin Varley voltage divider may be thought of as being equivalent to a digital
potentiometer.
However, it has an additional, but variable, resistance in series with the wiper arm, which goes to zero at
the full scale and zero settings.
This series resistance has no effect in balanced bridge type applications, where these dividers are
often used.
| Series | KVD-600 | KVD-700 |
| Calibration: | Requires external calibration. | Self calibrating; has internal oil bath. |
| Ratio Range: | 0 to 1.0 of input. | 0 to 1.0 input for 1.0 terminal;
0 to 1.1 of input for 1.1 terminal. |
| Resolution: | 0.1 ppm with 7 decades. | 0.1 ppm with 7 decades. |
| Absolute Linearity:
[Vout/Vin]-S where S is the dial setting. |
± 0.5 ppm | ±
0.1 ppm for S = 0.1 to 1.1;
± 0.1(10S)1/3 ppm for S = 0 to 0.1. |
| Short-Term Linearity Stability: | 0.2 ppm/30 days under standard laboratory conditions and VIN <100 V. |
0.1 ppm/30 days under standard
laboratory conditions and VIN <100 V. |
| Long-Term Linearity
Stability: |
± 2.0 ppm of input/year. | ±
1.0 ppm of input/year for S=0.1 to 1.1;
± (10S)2/3 ppm of input/year for S=0 to 0.1; Self calibration restores linearity to 0.1 ppm. |
| Temperature Coefficient of Linearity: | <± 0.2 ppm/° C. | <±
0.1 ppm °
C for S=0.1 to 1.1; <± 0.1 (10S)2/3 ppm/° C for S=0 to 0.1. |
| Power Coefficient of Linearity: | ± 1 ppm/watt. | <±
0.2 ppm of input/W for S=1.1 to 0.1; <± 0.2 (10S)2 ppm of input/W for S=0.1 to 0. |
| Maximum Input Power: | 2.5 watts; 5 watts intermittent. | 10 W at 1.0 INPUT; 11 W at 1.1 INPUT. |
| Maximum Input Voltage: | 1000 V | 1000 V at 1.0 input terminal;
1100 V at 1.1 input terminal; |
| Input Resistance: | 100 kOhm ± 50 ppm. | 100 kOhm ±
50 ppm at 1.0 INPUT;
110 kOhm ± 50 ppm at 1.1 INPUT. |
| Maximum Output Resistance: | 66 k, determined by shorting across the input and
measuring the resistance across the output terminals. |
|
| Terminals: | High quality low thermal emf gold plated tellurium copper binding posts. |
|
| Dimensions: cm | 48.3 cm W x 13.3 cm H x 18.5 cm D (19.0" x 5.25" x 7.3"). |
5.25" high rack panel; 13.3 H x 48.2 W x 33.0 D (5.25" x 19.0" x 13.0"). |
| Weight: | 4.1 kg (9 lb). | 8.2 kg (18 lb). |