Eti reference thermometer eti 222 055 p this reference thermometer from eti is a high accuracy pt100 instrument supplied with a 5 point ukas certificate of calibration each certificate indicates deviations from standards at various check points 18 0 40 70 and 100 deg c p p the reference thermometer is ideal for comparison checking the calibration and accuracy of other thermometers and probes when used in conjunction with a stable temperature heat or chill source the instrument me