IoTClass / Inside the measurement
Conceptual · not to scale

Inside a capacitive humidity sensor

Peel from the case to the element. Follow the readout through this conceptual model.

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The full text version below describes every layer. All measurement explanations are available without 3D.
Case: vented enclosureA white vented enclosure surrounds the humidity-sensor board.

Drag to rotate; pinch to zoom. With the view focused: arrow keys rotate, + / − zoom, 1–3 choose a layer, Home resets rotation and zoom. Step advances to the next layer; Reset returns to the case and default view. Layer buttons select a view directly. The page does not move on its own.

Layer 1 of 3 / Outside

Case: vented enclosure

A white vented enclosure surrounds the humidity-sensor board.

Teaching view: The white cover has openings above a green board. Peel away the cover to see the sensing parts; a moisture-sensitive film changes capacitance as it takes up water.

The measurement to rememberCapacitance rises as the moisture-sensitive film absorbs water. [Evidence-Based Comparison]

Full text version · every layer

1 · Case: vented enclosure

A white vented enclosure surrounds the humidity-sensor board.

Teaching view: The white cover has openings above a green board. Peel away the cover to see the sensing parts; a moisture-sensitive film changes capacitance as it takes up water.

2 · Readout: humidity and temperature

Temperature compensation is part of the humidity measurement. [Evidence-Based Comparison]

Teaching view: The green board carries a dark readout block, a pale humidity-sensing support, and a separate temperature element. Humidity changes the sensing capacitance, and the measurement also needs temperature compensation.

3 · Element: electrodes and moisture-sensitive film

Two electrodes surround a thin moisture-sensitive insulating film. [Evidence-Based Comparison]

Capacitance rises as the moisture-sensitive film absorbs water. [Evidence-Based Comparison]

Teaching view: Copper-colored electrode strips interleave on the pale support. The moisture-sensitive film between the electrodes takes up water, increasing capacitance; the readout uses that change to measure humidity.

Explode separates the proposed layers; X-ray makes the case translucent. These are teaching views. No commercial sensor construction or wiring is specified.