Temperature · Interactive Instrumentation Guide

Temperature Transmitter

Heat and cool the process. Compare temperature, sensor response, and the configured transmitter output.

Custom process schematic · not to scale · blue H connection / orange L connection, where applicable.

Paused — change any input

Equation and live calculation

I_ideal = 4 + 16(T − LRV)/(URV − LRV)

Live substitution appears when the demonstration loads.

PV = process value; LRV/URV = lower/upper range values; I = current in mA. Pressure calculations use kPa internally. Selected units apply to inputs, limits, diagrams, and readouts; changing units converts the same physical values without changing the current. Tank calculations use meters internally; z is positive above the bottom tap. ρ = 1000 × specific gravity in kg/m³; g = 9.80665 m/s². H in tank equations means measured height, not the H port. Entered LRV/URV define the current scaling; calculated empty/full tank DP values are reference checks. Set and Reset Points define switch operation; deadband is their absolute difference. Temperature reference equations use °C internally. Mercury pressure units use conventional NIST conversion factors. Vacuum entries are negative gauge pressure; the absolute-pressure readout remains nonnegative. Models assume ideal instantaneous response. Displayed current is limited to the nominal 4–20 mA range: I_display = clamp(I_ideal, 4, 20), where clamp holds a value at its lower or upper limit. This teaching limit does not reproduce manufacturer-specific saturation or alarm currents.

Where it is used

A temperature transmitter maps an engineering temperature range onto a standard current loop.

What the demonstration shows

The transmitter output is linear in temperature, even when the connected sensor is nonlinear.

Common mistake to avoid

Match the input range and units at both the transmitter and receiving system.

Model assumptions

Ideal proportional transfer with no damping or measurement error. The teaching model limits current to 4–20 mA; manufacturer-specific saturation and fault-current logic are excluded. Display-unit changes preserve the same physical values.

Technical references

NIST — Thermocouple reference functions

Educational model. Consult the instrument manual for installation, configuration, limits, and approved test procedures. No connection to live plant equipment is made.