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10-4 Analog Output
Temperature
The analog output voltage for temperature measurements depends on thermocouple type and
the selected units (°C, °F, or K). The 1.2V analog output is scaled to the maximum positive
temperature reading. For example, the measurement range for the Type J thermocouple is
-200°C to +760°C. For a 760°C reading, the analog output voltage will be 1.2V, and for a -200°C
reading, the analog output voltage will be –0.316V. The measurement ranges (in °C) for the
various thermocouple types are listed in the specifications (see
Appendix A ).
With Gain set to 1 and Offset set to 0, analog output voltage for temperature measurements
is calculated as follows:
Analog Output = 1.2 × Rdg/Rng*
* Rng is a magnitude. Therefore, it is always a positive value.
Example Calculations:
Type J, 100°C Reading Type J, –100°C Reading
Analog Output = 1.2 × 100/760 Analog Output = 1.2 × (–100/760)
= 158mV = –158mV
When using Gain and Offset, the calculation is expanded as follows:
Analog Output = (Gain × 1.2 × Rdg/Rng) – Offset
Ratio
Analog Output can be used with Ratio. When enabled, the analog output voltage is scaled to
a Ratio value of 1. That is, the analog output will be 1V for a Ratio result of 1. If, for example,
the Ratio is 0.4, analog output voltage will be 0.4V. Gain, Offset, and Analog Output Rel can
also be used. However, the maximum analog output is ±1.2V.