Works Calibration Of The K3607; Effect Of Cable Resistance - HBM K3607 Bedienungsanleitung

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Works calibration of the K3607

The K 3607 is calibrated in the factory under the following conditions:
− Ambient temperature: + 23
− Connector cable:
Kab 0238A−3 (included in the list of components supplied), cable length =
3 meters
Cross-section of each bridge excitation wire 1.5mm
− Internal excitation voltage resistance: v1Ω
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Effect of cable resistance

The cable effect for KAB0238A-3 cable is calibrated in at the factory. This
applies to four- and six-wire circuit at the end of the 3-meter long cable.
On subsequent connection in four-wire circuit, the output signal is reduced by
the K factor due to the resistance of the excitation wires.
The K factor is calcultated as follows:
Bridge resistance)
The resistance value of an excitation wire is used for the r term. In the case of
KAB0238A-3 cable this resistance r = 0.0118 Ω. According to the formula (1)
this gives a value of 0.99993 for the K factor. This means an absolute
calibration error of 0.007% if KAB0238A-3 is not used.
A switching step error also occurs. Depending on the position of switch S2 the
internal resistance of the K 3607 alters slightly, as does the effective excitation
voltage due to the cable resistance r.
The grading error of the percentage steps increases by some 0.02% at 10 Ω
of cable conductor resistance.
When connecting a six-wire circuit the cable effect is corrected and the K
factor = 1. No additional grading error occurs (internal excitation voltage
resistance < 1 Ω).
If KAB0238A-3 cable is not used, an absolute calibration error of the
corresponding size occurs. This means the output signal is increased by a
factor of K = 1.00007.
HBM
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A0833-3.0 en/de
K3607