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THERMOMETRY BRIDGE METROLOGY STANDARD |
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F18
Thermometry Bridge Primary
Standard. Resistance Thermometry Bridge. Accuracy +/- 0.1 ppm |
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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.
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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 Bridge can be used with one or more switchboxes for multi channel
calibration. |
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Features
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Bandwidth |
Selectable: 0.5, 0.1 or 0.02 Hz |
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External Standard |
AC/DC standard resistor or resistance thermometer |
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Sensor current |
0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50mA or x root 2 any value |
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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. |
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Bridge balancing modes |
Automatic: |
via full
self balance algorithm. |
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Manual: |
via front
panel switches (to 0.1 ppm) and analogue meter (interpolated to 0.01
ppm). |
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Self check modes |
Zero: |
verifies
bridge zero accuracy |
| Unity: |
verifies
bridge slope accuracy |
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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 metres for
25.5 Ohm SPRT referenced to a 25 Ohm resistor) |
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Quadrature balance |
Eliminates effects of thermometer, resistor and cable reactance |
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Active input guard |
Eliminates effects of leakage from any terminal to ground |
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Analogue output |
Null
balance: |
±10V
(unfiltered) |
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Programmable: |
0-10V (3
scale ranges) |
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Accessories |
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| SB148 |
10 channel auto/manual
multiplexer, with individual preset "keep warm" current |
| SB148/01 |
As SB148, with 4
individual "keep warm" currents per channel |
| SB158 |
Driver/interface for up
to 2 x SB148 or 5B1 48/01 multiplexers (Specify RS232 or IEEE |
| SB158/01 |
Driver/interface for up
to 6 x 5B148 or SB148/01 multiplexers (Specify R5232 or IEEE) |
| F18 AS1 System |
F18 complete with SB148
and SB158 multiplexer in 19"/1 6U cabinet complete with power
distribution and cutout |
| F18 AS2 System |
As AS1 system, but with
SB148/01 multiplexer |
| RW1, 10, 25, 100, 300 |
"Wilkins" AC/DC Standard
Resistor. Values: 1, 10, 25,100 and 300 ohms |
| RTWE |
Thermal enclosure for RW
resistors |
| FA1 |
Co-axial cable set with
BNC connectors at both ends |
| FA2 |
Co-axial cable set with
BNC connectors at one end |
| FA3 |
4 terminal to 2 x BNC
connector, adapter box |
| FA-KIT |
FA1, FA2 and FA3 cable
set |
| TMS |
ITS-90 temperature
measurement and data acquisition software |
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