Digital thermometer with LCD display

This is a thermometer with 3 1/2 digit LCD display for measuring the ambient temperature. The sensor is an integrated circuit S-8100BF, which is usually used for temperature compensation. This device includes also a 3 1/2 digit convertor ICL7106. The unit was ready for the first use in 1996. Later in 1999, I made some modifications to allow a better temperature calibration.

In 2012 I have dismantle this thermometer to use the same components and printed circuit board for a voltmeter.

Main sensor features are:
-linear output voltage: -8.1 mV / °C
-temperature range: from -40°C to 100 °C
-linearity: ±1% (-20°C to 80 °C)
-repeatability: ±0.3 °C
(for complete list of specifications, see [2])

Thermometer specification:
- measuring domain: from 0°C to 50°C (estimated)
- resolution: 0.1°C
- accuracy (estimated): ± 1°C
- powered from mains socket: 230 VAC
- Schematic diagram

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Reference links:
[1] - 3 1/2 digit A/D converter ICL7106/7107
[2] - CMOS temperature compensation IC: S-8100BF