HBM CANHEAD - Shunt resistor

Configuration
CANHEAD A01185_11_X00_00 HBM: public 23
6.1.1 Shunt resistor
A shunt resistor (1 mV/V) is incorporated in all the CANHEAD base modules
for single strain gages in a quarter bridge circuit (CB1014, CB1015 and
CB1016). Use a jumper setting to decide whether this internal shunt resistor or
an external one, for example a precision resistor with certification, is to be
used.
By using the following formula
S the requisite shunt for a required misalignment can be determined, or
S the misalignment for a given shunt can be determined
Misalignment by means of an internal shunt resistor
v = misalignment V
0
/V
s
in [V/V]
R
e
= value of the supplementary resistor
R
s
= value of the shunt resistor
Given: R
e
, R
s
Wanted: v
R' = (R
e
* R
s
) / (R
e
+ R
s
) Example: R
e
= 350 R
s
= 87325 
v = -0.5 * (R
e
- R') / (R
e
+ R') v = -0.001 V/V = 1.000 mV/V
Given: R
e
, v Wanted: Rs
R' = R
e
* ( ( 0.5 + v ) / ( 0.5 - v) )Example:R
s
= 350 v = 1.000 mV/V
Rs = 1 / ( 1/R' - 1/R
e
)R
s
= 87325  = 87.325 k
Measurement errors caused by the effect of the cable resistor in the
unregulated three‐wire circuit (CB1014) can be corrected by proper use of the
shunt calibration.
Loss of sensitivity = R
e
/ (R
e
+ R
cab
) Correction by the shunt
calibration in conjunction with
the CANHEAD correction
function (see Chapter 10.1).
Offset error = 1/2 (R
cab
/ R
e
) Correction by the CANHEAD
zeroing function