F18 Thermometry Bridge Primary Standard. Resistance Thermometry Bridge.
The Model F18 Thermometry Bridge Primary Standard is designed specifically for resistance thermometry to
provide you with the best possible accuracy.
The 25Hz or 75Hz operating frequency provides fast, continuous measurement with high immunity to thermal
emfs and supply frequency noise sources.
Practical measurements involve cables, connectors and imperfect operating environments, the F18
Thermometry Bridge achieves its full specification under a wide range of real operating conditions.
Thermometry Resistance Bridge
| Model | Description |
|---|---|
| F18 | Thermometry Bridge Primary Standard. |
The F18 Thermometry Bridge includes a wide range of features specifically tailored for temperature metrology.
These include programmable excitation current, root 2 current, analogue outputs, selectable source
impedance, gain and filter bandwidth.
Manual or automatic bridge balancing together with manual or
automatic control (IEEE interface) of the instrument ensure that the F18 can provide solutions in a wide
range of measurement applications.
The F18 Thermometry Resistance Bridge can be used with one or more switchboxes for multi channel
calibration.
| Bandwidth | Selectable: 0.5, 0.1 or 0.02 Hz | |
| External Standard | AC/DC standard resistor or resistance thermometer | |
| Sensor current | 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50mA or x root 2 any value | |
| Sensor current frequency | User selectable frequencies: | 25 or 75
Hz with 50 Hz supply 30 or 90 Hz with 60 Hz supply Phase locked to supply frequency. |
| Bridge balancing modes | Automatic: | via full self balance algorithm. |
| Manual: | via
front panel switches (to 0.1 ppm) and analogue meter. |
|
| Self check modes | Zero: | verifies bridge zero accuracy |
| Unity: | verifies bridge slope accuracy | |
| Lead connections |
True four wire connections for
resistance thermometer (Rt) and standard resistor (Rs). Accuracy
is unaffected by series lead resistance, permitting measurements
with long cables (100 meters for 25.5 Ohm SPRT referenced to a
25 Ohm resistor) |
|
| Quadrature balance | Eliminates effects of thermometer, resistor and cable reactance | |
| Active input guard | Eliminates effects of leakage from any terminal to ground | |
| Analogue output | Null balance: | ±10V (unfiltered) |
| Programmable: | 0-10V (3 scale ranges) | |