Heat-Pulse-/ Frost-Pulse-Method

Heat Pulse Method

For the heat-up or heat-pulse method (HPM), a hybrid cable consisting of glass fibers and electrical conductors is used. An electrical voltage is applied to these conductors so that a short-circuit current flows. This causes the entire cable to heat up. The resulting temperature rise in the cable is measured with the glass fibers. In addition to the conductive heating of the cable environment, an additional advective heat transport occurs when a fluid, e.g. water, flows around the cable, which leads to a significantly lower heating of the cable. In this way, flow processes can be detected and thus leakages located. Through calculations, both the flow velocity of the fluid and the thermal parameters of the surrounding material can be determined.

Frost pulse method

For applications where the heating method is technically too complex, GTC® has developed the Frost Pulse Method (FPM). In contrast to the HPM, a refrigerant is used which is introduced into a temperature probe tube. The temperature rise is then measured with temperature sensors and evaluated in the same way as HPM. This method has the advantage that no electrical energy has to be available; the disadvantage is that only a qualitative evaluation can be made.