Miniature metallised polypropylene film capacitors
26 Jan 2000
Passive Components
Avnet Kopp
BC Components' capacitive humidity sensor operates by sensing changes in capacitance of a thin-film polymer membrane as it absorbs moisture from its surroundings. Compared with many alternatives, the company claims it is simple to operate, highly reliable and fast. It also has long-term characteristics unaffected by condensation of water on the membrane surface and other aggressive pollutants in the air.
Applications are home hygrometers, weather stations, air-conditioners, climate controllers and tumble dryers.
Designed for a measuring range between 10% and 90% relative humidity the sensor's relatively linear characteristic allows it to be easily incorporated into simple, inexpensive measuring circuitry.
The sensor is made up of a polymer film coated on both sides with a very thin air-permeable gold layer to form a capacitive element. The film is clamped between spring contacts inside a perforated plastic housing and changes in relative humidity (RH) cause a change in dielectric constant of the polymer film leading to a change of sensor capacitance. BC Components says the relationship between sensor capacitance and relative humidity is a rather simple one which means that the sensor can easily be incorporated into an electrical measuring circuit.
Sensor specifications are: humidity range 10 to 90% RH; capacitance (+25°C, 43% RH, 100 kHz), 122 ±15% pF; sensitivity between 12 and 75% RH, 0,4 ±0,05 pF/% RH; frequency range, 1 to 1000 kHz; response time between 10 and 43% RH, <3 min and between 48 and 90% RH, <5 min; operating and storage temperature range, -25 to +85°C.
The units measure 20,0 x 15,5 x 5,0 mm with lead distance 5,08 mm.
Further reading:
High-endurance polymer tantalum capacitors
Passive Components
Panasonic Industry TDC Series POSCAP polymer tantalum capacitors deliver high endurance and reliable performance in demanding, high-temperature environments.
Read more...
Thin-film inductors for optical transceivers
RS South Africa
Passive Components
TDK has expanded its PLEC69B series (1,2 x 0,6 x 0,95 mm – L x W x H) of thin-film inductors, used for separating the data signal from the power in optical transceivers in AI data centres.
Read more...
Low-resistance MLCCs
RS South Africa
Passive Components
TDK Corporation has expanded its CN series of low-resistance soft-termination multilayer ceramic capacitors; achieving 22 nF capacitance in the 3225 case size.
Read more...
Ferrite cores with different shapes
RS South Africa
Passive Components
TDK Corporation has introduced a variety of new large-size ferrite cores with different core shapes, making this the industry’s largest lineup of shapes, sizes, and materials for such large cores.
Read more...
Vibration-resistant axial capacitors
RS South Africa
Passive Components
TDK Corporation has unveiled the B41699 and B41799 series of ultra-compact aluminium electrolytic capacitors, engineered to withstand operating temperatures of up to 140°C.
Read more...
Capacitors for demanding industrial applications
Passive Components
TDK Corporation has announced its X1 capacitors of the EPCOS B3291xH/J4 series for power line filtering of electromagnetic interferences in demanding automotive and industrial applications with a rated AC voltage of up to 480 V.
Read more...
Wide frequency range inductors
RS South Africa
Passive Components
TDK Corporation has expanded its ADL4524VL series
(4,5 x 2,4 x 2,6 mm – L x W x H) of wire-wound inductors for automotive power-over-coax.
Read more...
Cutting-edge hybrid capacitors
Avnet Silica
Passive Components
Panasonic Industry recently announced the launch of the ZVU Series Hybrid Capacitors, a cutting-edge solution tailored to meet the escalating demands of advanced electronic systems.
Read more...
Low-profile tantalum chip capacitors
Electrocomp
Passive Components
These general-purpose tantalum capacitors from Kyocera AVX are available in multiple case sizes with low profile options.
Read more...
Coupled inductor for high-performance applications
Passive Components
This coil with MnZn core is characterised by its high permeability and extremely low RDC values, which achieves excellent power density and very high efficiency.
Read more...
printer friendly version