Operation Of The 1041 - Time Electronics 1041 Manuel Technique

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2. Operation of the 1041

The 1041 is a compact, robust and accurate decade resistance box designed to meet the
needs of both industry and education. Housed in a robust metal case, the compact
construction makes it easily portable.
Metal film resistors are used to obtain the high stability and low temperature co-efficient.
It is imperative that the switch setting should be unambiguous in order to avoid misreading
the set value. To prevent misreading, the 1041 incorporates a unique colour coding system
to divide the setting into 2 groups corresponding to milli-ohms and ohms.
Resistance is simulated by dialing the value required using the thumbwheel switches. This
enabled precise setting with a clear unambiguous indication.
For example—to simulate 138.51Ω equivalent to 100
°
C pt100 (ITS-90):
Set the 100Ω bank decade switch to 1,
the 10Ω bank decade switch to 3,
the 1Ω bank decade switch to 8,
the 0.1Ω bank decade switch to 5,
the 0.01Ω bank decade switch, set to 1.
Connection to the box is via 4mm terminal Posts, 4mm plugs or stripped wire connections
can be used.
The red and black terminals connect to the resistance and the grey terminal is connected to
the case for screening purposes.
Special attention has been given to the problem of reliability of operation. A special multiple
gold contact switch arrangement ensures that a back-up contact is always available to take
over should a failure occur.
Note: All resistance boxes have a residual resistance, i.e. when the dials are set to zero a
small resistance remains. If you are making precision measurements or recalibrating the
instrument, this residual value must be subtracted from all measurements.
1041 Technical Manual 3