USB-100 Fujitsu Semiconductor America Inc, USB-100 Datasheet - Page 94

• Manufacturer Part Number: USB-100
• Description: KIT STARTER FOR USB
• Manufacturer: Fujitsu Semiconductor America Inc
• Type: MCUr

Specifications of USB-100

• Contents: Board, Cable
• For Use With/related Products: MB91F662
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 865-1108

affected by changes in its own materials caused by substances in the air, sometimes
leading to performance loss. The material used in the sensor to detect humidity defines
its type, such as high-molecular, metallic oxide, or electrolytic.
The high-molecular film absorbs and releases moisture, thus creating a change in its
permittivity which is used to measure the relative humidity in air.
electrodes, much like a capacitor. The permittivity change in the high-molecular film
creates a measureable change in the capacitor's capacity. The electrodes are made of
an extremely thin metal film that permits the passage of moisture as it is absorbed or
released by the high-molecular film. A high-molecular humidity sensor can be of the
capacity changing or resistance changing type. The explanation thus far is for a capacity
changing type. The resistance changing type is made by affixing moisture sensitive
material on a comb-like electrode and is simpler in construction than the capacity type.
An added benefit of the resistance type is that it is not affected by the capacity of the
wire leads, allowing wiring lengths to be as long as necessary.
We will explain the most common type of humidity sensor, the high-molecular sensor.
One way of making this sensor is to place the high-molecular material between two
Substrate
Capacity type
Electrode
Figure 8.2-1 Structure of a humidity sensor
(moisture sensitive
High-molecular
material)
material
93
Substrate
Electrode (comb-like)
Resistance type
(moisture sensitive
High-molecular
material)
material