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| A strain gauge. Note the thin wires forming the strain gauge. |
Strain gauge This is glued onto an aluminium bar as part of a load cell in an electronic balance. |
Load cell in an electronic balance. There are four strain gauges, one on the top and bottom of each hole in the aluminium bar of the load cell |
A thermocouple. Note the junction of the two different metal wires. |
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| A Passive Infra Red (PIR) sensor unit. Note the Infrared sensor in the middle and the LDR beneath. The Triac for switching the lamp is mounted on the heatsink on the left. |
The lens from a PIR. Note the structure of the lenses which are used to create a change in the heat signal reaching the IR sensor as the hot object moves between the zones on the lenses. |
Thermistors ntc The two outer ones were used as surge limiters in switched mode power supplies. |
Photodiode The photodiode pn junction is visible in the photodiode's window. |
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| Light Dependent Resistor. The light sensitive region is made from selenium. |
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