Existem algumas maneiras de sentir o gelo em uma célula. O DOT tem um documento que descreve os vários tipos de sensores.
Primeiramente, os aviões têm luzes de gelo que se projetam nas asas para que possam ser inspecionadas visualmente.
Existem sensores completamente óticos que usam uma variedade de métodos para detectar o gelo.
Existem também alguns dispositivos eletromecânicos, aqui estão alguns exemplos, o resto está descrito no Documento DOT .
Penny and Giles
The Penny and Giles system uses a probe type sensor that measures ice buildup in terms of Liquid Water Content (LWC). This system was designed specifically for use on helicopters and is available for all turbine-powered helicopters.
Rosemount
The sensing probe is driven magnetostrictively to vibrate at its resonant frequency of 40,000 Hz. As the ice detector enters an icing environment, ice collects on the sensing probe. The added mass of the accreted ice causes the frequency of the sensing probe to decrease in accordance with the laws of classical mechanics.
Sunstrand
The Sunstrand system uses a mounted probe with a sensing surface facing the airstream. Beta particles are released from a Strontium 90 Radiation Source and are collimated by a specially shaped window in the probe housing. These particles pass across the sensing surface to a Geiger-Muller tube. High voltage is applied to the Geiger-Muller tube to enable it to detect the radiation emitted by the Strontium 90 source. Ice accretion on the probe decreases the beta particles detected by the tube. When the particle count drops below a pre-set level, a pulse rate discriminating amplifier energizes an icing signal visible to the flight crew. At this time a heater inside the probe is activated, the ice is removed from the probe, and the probe is ready to begin another icing cycle.
Alguns deles funcionarão em uma situação estática, enquanto outros podem exigir a passagem de um ambiente sem congelamento para uma situação de congelamento.