456 Controlled AC DC resistor
456 Controlled AC DC resistor
Nominal temperature resistance coefficient: +0.02 ppm / °C
ISOTECH - 456 CONTROLLED AC DC RESISTOR
Square Temperature Controlled Fixed Resistors
With Isotech's model 456, by temperature regulating an otherwise very stable resistor, you can achieve performance close to the best available at a surprisingly low price. The resistor is oil-filled and hermetically sealed.
Long-term stable
The hermetic seal eliminates the ingress of moisture and oxygen, both of which play a role in the long-term degradation of unsealed resistors. A further improvement in both short- and long-term stability is achieved by oil filling. The oil also acts as a thermal conductor, allowing the unit to accept short periods of overload without degradation.
Accuracy of ±0.005%
With accuracies of ±0.005%, a wide resistance range, and long-term operation of less than 5 ppm, these devices are practically secondary standards that can be kept in a laboratory as references to calibrate other devices.
The resistor is kept in a temperature-controlled environment heated to 30°C ±0.1°C. Other temperatures are available on special order. The heater requires 2 watts at 5V, which can be supplied by a battery or an unregulated DC supply. In an ambient temperature of 20°C, the resistor's heating element will heat up in typically 30 minutes, and an LED will show when the temperature has been reached. In addition, there is a test pocket so that the temperature of the resistor can be monitored if necessary.
Stability of 0.1 ppm/month or better can be expected. Standard models are: 10, 25, 100, 1000, 10,000Ω. For other values please contact us. For the highest quality of traceability we recommend the 456 which is UKAS certified.
