How can we help? +44 (0)1704 543830 | info@isotech.co.uk

By temperature controlling an otherwise very stable resistor a performance close to the very best available World-wide can be achieved at a surprisingly low price. The resistor itself is oil filled and hermetically sealed.

The function of hermetic sealing is to eliminate the ingress of moisture and oxygen both of which play a role in the long term degradation of unsealed resistors. A further enhancement in both short and long term stability is achieved by oil filling. The oil also acts as a thermal conductor allowing the device to accept short periods of overload without degradation.

With accuracies of ±0.005%, a wide resistance range and long term drift of less than 5ppm, these devices are virtually secondary standards that can be kept in a laboratory as references to calibrate other devices.

The Resistor is held in a temperature controlled environment heated to 30°C ±0.1°C other temperatures are available to special order. The heater requires 2 watts at 5V which can be supplied by a battery or an unregulated DC supply. In an ambient of 20°C the Resistor’s heater will warm up in typically 30 minutes, and an LED shows when the temperature has been reached. A test pocket is provided so that the resistors’ temperature can be monitored if required.

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 Isotech.

For the highest quality traceability we recommend that the 456 be UKAS Certified. We can offer the 2 Sigma Uncertainties shown in the table.

Technical FeatureValue
Model456
Rating0.5 Watt
StabilityTypically 1ppm per year at 1mA
TraceabilityA Traceability certificate accompanies your 456 to the 2 sigma uncertainties shown.
Induction0.08μH typical
Capacitance0.5pF
Dimensions114 x 110 x 96mm (in box)
Weight1kg (including box) 550g (excluding box)
How to order456 Temperature Controlled Fixed AC/DC Resistor. Please specify ohmic value. State with UKAS Calibration or without UKAS Calibration.

Temperature Controlled Fixed Resistors

Nominal Temperature Coefficient of Resistance: +0.02ppm/°C (with temperature control on) 18 to 25°C

By temperature controlling an otherwise very stable resistor a performance close to the very best available World-wide can be achieved at a surprisingly low price.

  • Nominal Temperature Coefficient of Resistance: +0.02ppm/°C (with temperature control on) 18 to 25°C
  • Power Rating: 0.5 Watt at +25°C
  • Standard models: 10, 25, 100, 1000 and 10,000Ω
  • Current Noise: <0.010µV (RMS) / Volt of Applied Voltage
  • Thermal EMF: 0.1µV/°C Max; 0.05µV/°C Typical
  • The most precise and stable resistors available
  • Impervious to harmful environments - oil filled

Or call +44 01704 543830

youtube linkedin