Section 4
08 November 2022
2 November, 2016
4-1
4. MAINTENANCE
4.1.
INTRODUCTION
This section covers troubleshooting, repair and alignment of the model 6622A Series Automatic
DCC Resistance/Thermometry Bridge.
4.2.
TEMPERATURE RATIO VERIFICATION
This section outlines the recommended thermometry based ratio verification requirements for the
model 6622A with the T-Option installed.
4.2.1.
PURPOSE
The purpose of the procedure in this section is to assure that the model 6622A Series Bridge
functions properly and meets the manufacturer’s additional specifications for T-Option. It is
recommended that these procedures be performed after any corrective maintenance activity, or if
the operator perceives a problem.
It is recommended that all of these procedures be performed on an annual basis to verify
performance of the model 6622A for its recertification.
4.2.2.
EQUIPMENT REQUIRED
The following equipment is required for this procedure.
-
10
Ω
standard resistor, stable to ± 0.01
µΩ
/
Ω
over a 24 hour period (x2)
-
100
Ω
standard resistor, stable to ± 0.01
µΩ
/
Ω
over a 24 hour period (x2)
-
1 k
Ω
standard resistor, stable to ± 0.01
µΩ
/
Ω
over a 24 hour period (x2)
-
25
Ω
standard resistor, stable to ± 0.01
µΩ
/
Ω
over a 24 hour period
-
400
Ω
standard resistor, stable to ± 0.2
µΩ
/
Ω
over a 24 hour period
-
Temperature controlled environment sufficient to maintain the reference and working standard
resistors to their specified uncertainties
Note: The eight standard resistors are available in the optional model 6634 Resistance
Standard.
Summary of Contents for 6622A Series
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