NOISE and 5B's
CALCULATIONS TO GET TC TEMPERATURE VS MODULE OUTPUT
First you need to get the TC voltage from the voltage output of the
module. The output from our modules range from 5-10 volts unipolar or
bipolar. There is a gain and offset incorporated in every module to bring
the TC voltage up to the level of 5 to 10 volts. There is no need to worry
about CJC because there are sensors on the backplane that compensate at
every module location. Follow the following steps to find the gain and offset.
1. The basic formula for calculating the gain and offset of our modules is:
Vout = Gain * (Vin - Zero)
You need to find the differential span for Vout and Vin. To find
this apply the following:
Vspan = Vhi - Vlo
Note: Vspan is always an absolute value.
EXAMPLE: 5B37-J-01
Vin(span) = 47.544mv (-100 degC[-4.632mv] to
+760 degC[42.922mv]);
Vout(span) = 5V (0 to +5V).
2. To find an output voltage for a given TC find the equivilent mv value and
apply...
Vout = Gain *(Vin - Vzero)
Vzero=input voltage for output to equal Vlo(0 volts) (i.e. -4.632mv)
3. Find gain: Gain=Vout(span)/Vin(span)
EXAMPLE: 5B37-J-01
Gain=5/47.544mv
Gain=105.143
So at 28 degC input(1.432mv for type J) would give a Vout of:
Vout =105.143 *(1.432mv -(-4.632mv))
Vout =.6375
To find a input voltage based on an output value:
Vin = (Vout/Gain) + Vzero
EXAMPLE: Use Vout from previous example
Vin = (.6375/105.143) + (-4.632mv)
Vin = 1.432mv (28 degC)
Therefore the Gain = 116.5 and offset = -4.632 for the 5B37-J-01.
4. Once you have the Gain and offset of the module you can find the output
voltage of the TC and from there use the tables or polynomials to find the
correlating temperature. This information can be found in the Omega catalogs.