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THERMOMETRY BRIDGE METROLOGY STANDARD |
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F900
Thermometry Bridge Primary Standard. Resistance Thermometry Bridge |
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The Model
F900 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 F900 achieves its full specification under a wide
range of real operating conditions.
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Design
features such as the unique input guard
ensure that you really can
obtain the specified
accuracy of 20ppb over the
range of 0.2 ohms to
390
ohms.
This equates to a temperature measurement
accuracy of 5 micro K for a 25.5 ohm SPRT
referenced to a 25 ohm reference resistor. |
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The F900 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 F900 can
provide solutions
in a wide range of measurement applications.
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Features
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Bandwidth |
Selectable: 0.5, 0.2, 0.1, 0.05,
0.02, 0.005, 0.002, 0.001 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:
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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.
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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 meters 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) |
| F900 AS1 System |
F900 complete with SB148
and SB158 multiplexer in 19"/1 6U cabinet complete with power
distribution and cutout |
| F900 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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