Typically, polymer absorption (PA) sensors are composed of an elastomeric polymer matrix that is embedded with micro- and nano-sized conducting particles. The resulting composite material is deposited between two electrodes on a printed circuit board (PCB) and has a characteristic baseline resistance. PA sensors operate via absorption and subsequent matrix expansion (swelling) resulting from contact with target hydrocarbons. Upon swelling, the interparticle distance of the embedded conducting micro- and nanoparticles increases, resulting in a change in the sensor's baseline resistance. If the detected change in resistance is greater than a certain applied threshold, then this can be used by an external system to trigger an alarm.
Commercially available polymer absorption (PA) sensor technologies have not changed considerably since they were first developed in the mid-1950s. Two main factors contributed to the developmental stagnation:
Syscor, working closely industry leaders, has designed and produced a new generation of hydrocarbon detection sensor technology that overcomes the limitations of previous commercial PA sensors. Syscor’s solution comprises three distinctive, thoroughly tested and systematically qualified PA sensor formulations that detect hydrocarbons (C3 and heavier) reliably in air, on water surfaces and when fully immersed in water. Furthermore, they are designed to operate in a wide range of environments (icy, wet, humid, or dry) and temperatures (between -50 and +50 °C) without generating false alarms triggered by naturally occurring methane.
PA sensors are housed in stainless steel sensor transducers that are designed specifically for use with the Field Transmitters used with the Syscor FR-Tracker and HC-Tracker Monitoring Systems. Current applications of these sensors include floating roof monitoring and hydrocarbon leak detection in facilities, underground and in water bodies.