In trials, FOTEMP fibre-optic temperature measurement systems from Calex Electronics have been able to measure the temperature of liquid Helium down to -269ºC, just four degrees above absolute zero. This outstanding performance is available on all models in the FOTEMP series, and gives them a full temperature range of -269ºC to 300ºC. These measurements are achieved using completely non-metallic fibre-optic probes with a specific heat capacity of 1mJ per gram per ºK, and a heat conduction of just a thousandth that of conventional electrical probes.
Different fibre-optic probes are available to suit individual applications, offering various dimensions, lengths and material compositions. Probe diameters range from 0.45mm to 2mm, with lengths of up to 20m available. Different probes can be connected to the FOTEMP units as required; all that needs to be done is to run a quick and simple calibration procedure from the front controls or the supplied software via a PC. This flexibility allows one FOTEMP system to use many different fibre-optic probes and tackle many different applications.
FOTEMP models are available as stand alone systems with front mounted controls and displays, providing individual analogue outputs for each fibre-optic probe and RS-232 digital communications. Compact single-channel OEM systems are also available without built-in controls or displays, instead providing just one analogue output and a digital interface.