Unique hygroscopic fibres with outstanding durability
GALLTEC® has developed a synthetic fibre that changes its length depending on the humidity – it has long term stability and is 100 % waterproof.
The humidity measuring element manufactured by Galltec+Mela under the name POLYGA® comprises multiple synthetic fabric bands, which in turn are made up of 90 individual fibres of 3 μm in diameter. A special method is used to give these fibres hygroscopic properties, i.e. they absorb and desorb moisture. The fan-shaped measuring element is fitted inside the products so that it is protected against coarse dust particles and dirt, and is maintenance-free in ordinary ambient air.
Humidity control with no external power supply required
The measuring element is washable and ideal for use in high humidity. How it works is simple: as the length of the fibre changes, the microswitch on the measuring element is activated at the preselected humidity setpoint. Reliable without electronics or auxiliary power!
Typical applications
In many monitoring tasks, nothing beats reliable mechanics for which a power supply is not required. A typical situation is one in which air humidity must be monitored or controlled. This kind of application often arises in museums, warehouses, production areas, ripening facilities for fruit and vegetables, bakeries, mushroom cultivation, building air conditioning, etc. Depending on the situation, the appropriate humidifiers, fans, dryers and other actuators need to be controlled.
POLYGA® fibres are used for two types of instruments:
Advantages
- Excellent durability
- Reliable
- Auxiliary power
- Maintenance-free
- Robustness
- 100 % waterproof
- Insensitive to condensation
- Long-term stability in high humidity (fibre)
More information
Definitions, terms, measuring methods
Maintenance instructions
Absorption Principle
Hygrostat
The changes in the length of the POLYGA® fibers are transmitted to a microswitch. This type of humidity switch does not require any additional energy.
Hygrostat with Polyga
Humidity transmitter
The changes in the length of the POLYGA® fibers are converted into electrical resistance values, which are either output directly (passive transmitters) or converted into analog standard signals (active transmitters).
Transmitter with Polyga