Teledyne HFM-300 Automobile Parts User Manual


 
Manual: 151-082010 300-302 Series Page 14 of 31
Fig. 2.8
2.12. Temperature Coefficients
As the ambient temperature of
the instrument changes from
the original calibration
temperature, errors will be
introduced into the output of
the instrument. The
Temperature Coefficient of
Zero describes the change in
the output that is seen at zero
flow. This error is added to the
overall output signal regardless
of flow, but can be eliminated
by merely adjusting the zero
potentiometer of the flow
meter/controller to read zero
volts at zero flow conditions.
The Temperature Coefficient of
Span describes the change in
output after the zero error is
eliminated. This error cannot
be eliminated, but can be
compensated for
mathematically if necessary.
The curve pictured in Figure 2.8
shows the span error in percent
of point as a function of
temperature assuming 23
0
C is
the calibration temperature.