Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 139)

Publication 900-UM007D-EN-E - January 2011
Parameter Adjustments & Application Considerations 4-3
2-Point Shift
Overview
The 2-point shift can be applied to thermocouple, RTD, and a non-contact
sensor (infrared type K thermocouple).
Figure 4.8 — Temperature Limit Shift Value
• The input temperature range of the temperature sensors can be shifted
by setting an individual value for the upper and lower end points of the
sensor range. This means that the shift can be applied equally across the
range with separate values for each end of the range. For example, if the
Upper-Limit value is set to 2
°C and the Lower-Limit value is set to 1
°C, the sensor range is shifted by an average of 1.5 °C at the 50% input.
• Set the Upper-Limit value in the Upper-Limit Temperature Input Shift
Value parameter and the Lower-Limit value in the Lower-Limit
Temperature Input Shift Value parameter.
Figure 4.9 — Two-Point Shift
How to Calculate Input Shift Values
When a non-contact temperature sensor (for example, OMRON ES1B sensor)
is connected to the Bulletin 900-TC8, 900-TC16, or 900-TC32, an offset of
several degrees to several tenths of a degree can occur. For this reason, it may
be desirable to offset the readout value by 1-point or 2-point shift as described
here.
insh
insl
Upper-limit
temperature
input shift value
Lower-limit
temperature
input shift value
Input
Temperature
Upper-limit
value
Lower-limit value
Upper-limit temperature input shift value
After shift
Before shift
Lower-limit temperature
input shift value
100
0