Tip 1: Bond or bind the sensor to the object, using a heat transfer compound where appropriate, and secure the leads along a convenient route to the instrumentation. Lightly cover the sensor to protect it from draughts or external heat sources. Good results should be obtainable provided that interfering heat flows are small - take care that attaching the sensor does not change the temperature of the object, and that self-heating due to the measuring current is not excessive.

Tip 2: For hot or cold solids, where there are large heat flows, a surface measurement is likely to be problematical. A better result is obtained if the probe can be inserted in a hole drilled in the object, deeply enough that immersion errors are small. This is the principle of the ‘metal block calibrator’(discussed later).

Tip 3: To make good temperature measurements in solids the air gap between the probe and the object (or block in the calibrator) should be small so that they are in intimate contact. In some cases it may be acceptable to improve it by using a heat-transfer fluid or compound, but immersion errors, as indicated above, are still likely to be significant. Immersion tests should be done, as recommended for liquids. However, in this case temperature gradients in the object or block may make it difficult to interpret the results.

In summary, drilling holes and inserting probes in an object to facilitate measurement is invasive, and it cannot often be done in process industry. At high temperatures, as in the steel industry, it is common to use radiation thermometry if the surface is exposed, coupled with theoretical modelling to estimate the internal temperature.