Guarded High Resistance Hamon Transfer Standards
- FULLY GUARDED DESIGN
- 1 MΩ / STEP TO 1 TΩ / STEP
- FOR USE IN AIR
- INTERNAL TEMPERATURE SENSOR
Guarded high resistance transfer standards allow accurate 100:1 build-up of high resistance.
Each device contains ten nominally equal resistors permanently connected in series. A commutator cable assembly allows connection of the ten resistors in parallel, giving 1/100th the series resistance. Other ratios are easily made.
The 1 & 10 megohm resistors are wound from specially selected wire to provide matched temperature and power coefficients. Higher values are of specially specified precious metal oxide construction.
The internal guard network is made with resistors nominally equal to the main resistor values, allowing uniform guarding in any configuration, and in any ratio measurement.
Each high resistance transfer standard is provided with a commutator cable assembly which can be connected to some or all the resistors, allowing intermediate ratios to be realized.
Each Hamon includes an internal thermistor for monitoring temperature during use.
All models are supplied with NIST traceable calibration data, including voltage coefficient characterization.
Low resistance Hamon transfer standards, based on the Leeds & Northrup design, are also available.
For the highest commercially available accuracy in high resistance, please see our unique temperature stabilized Multiple High Resistance Standard, model MHS. Individual guarded resistance standards, designed for laboratory reference use, are also available.
| Model | Parallel Resistance |
Series Resistance |
Series- Parallel |
| 306 | 100 KΩ | 10 MΩ | 1 MΩ |
| 307 | 1 MΩ | 100 MΩ | 10 MΩ |
| 308 | 10 MΩ | 1 GΩ | 100 MΩ |
| 309 | 100 MΩ | 10 GΩ | 1 GΩ |
| 310 | 1 GΩ | 100 GΩ | 10 GΩ |
| 311 | 10 GΩ | 1 TΩ | 100 GΩ |
| 312 | 100 GΩ | 10 TΩ | 1 TΩ |
All resistance standards carry a five year warrantee.
