Nowadays thermopile reactor sensors and pyroelectric sensors commonly used in daily life. However, are they sharing the same scientific principles? What are the differences between them?
A thermopile reactor is a component that converts temperature difference and electric energy into each other. It consists of two or more thermocouples connected in series. The thermopile potential output is superimposed on each other, which can be used to measure slight temperature difference or average temperature.
When the temperature is measured by the thermopile sensor, the potential difference generated by a single thermocouple is too small to be measured, and the large expense of using high precision operational amplifier can be saved.
Structurally, the thermopile stack consists of multiple thermocouples. The radiation receiving surface is divided into several blocks, each of which is connected by a thermocouple. According to different uses, the practical thermopile reactor can be made into filament type and film type, and can also be made into multi-channel type and array type devices.
the thermopile infrared detector can be configured with various lenses and filters in various application scenarios such as temperature measurement, qualitative/quantitative analysis of gas composition, medical equipment, etc.
At present, it has been widely used in the fields of forehead temperature gun, ear temperature gun, intelligent home appliance, lamp switch, food temperature detection and so on!
Let's start with what pyroelectric effect means.
When some crystals are heated, such as Lithium tantalate, triglycopeptide sulfate, the two ends of the crystal will produce an equal number of charges with opposite symbols. Brewster formally named this phenomenon "pyroelectric" in year 1842. Infrared pyroelectric sensor is a thermopile infrared sensor based on pyroelectric effect.
The infrared sensor consists of three parts: sensitive unit, impedance converter and filter window. The compensated pyroelectric sensor also has a temperature compensation element. In order to prevent the external environment from interfering with signal output, the above components are vacuum encapsulated in a metal camp.
Pyroelectric materials have been widely used in human induction, security alarm, flame detection, noxious gas analysis and many other fields.