Thermopile shine da wata ake kawo zuwa kuli na harsuna da amfani da efektin thermoelectric.

Yana da thermocouples goma sha'awa, wadannan su ne maimakon kayan kula da mutane daban-daban da suka sami voltage idan an baka da farko da jiki. An kofar thermocouples a kan siri ko kuma kafin kafin don ya shiga thermopile, wanda yake taka da voltage mai yawa daidai da thermocouple gaba daya. Ana amfani da thermopiles don abubuwa da dama, kamar ci gadi, kula kasa, da kuma tabbatar da infa radiya.

Yadda Ya Shiga Thermopile?

Thermopile ya shiga da amfani da efektin thermoelectric, wanda yana nufin cikakken bayyana farko da jiki zuwa voltage da kuma vice versa. An samu wannan efekti a shekarar 1826 da Thomas Seebeck, wanda ya sanin cewa aiki da maimakon kayan kula biyu ta faru voltage idan babban fuskantar tare da jiki da kuma babban fuskantar harsuna.

Thermopile shine siri da thermocouples, kila ɗaya na da maimakon kayan kula biyu da masu power thermoelectric mai yawa da kutukan abubuwa.

Power thermoelectric shine bayanin yadda material ya faru voltage per unit temperature difference. Su kan fuskantar biyu, faduwa da harsuna. Faduwar fuskantar suna da a tsakiyar da take da jiki mai yawa, amma fuskantar harsuna suna da a tsakiyar da take da jiki mai harsuna. Farko da jiki a kan fuskantar faduwa da harsuna yana buƙaci electric current zuwa circuit, wanda yake faru voltage output.

Voltage output na thermopile ana iya zama da farko da temperature difference across the device da kuma adadin pairs na thermocouple.

Constant of proportionality shine Seebeck coefficient, wanda ake bayyana a volts per kelvin (V/K) ko millivolts per kelvin (mV/K). Seebeck coefficient yana neman da type da combination na metals da ake amfani da su a cikin thermocouples.

Diagram ta taka da thermopile na gaba daya da pairs na thermocouple biyu da suka kofar siri.

Fuskantar faduwar thermocouple biyu na T1, amma fuskantar harsunar thermocouple biyu na T2. Voltage output daga thermopile, ΔV, yana iya zama da farko da temperature difference, ΔT ko T1 – T2, across the thermal resistance layer da kuma adadin pairs na thermocouple. Thermal resistance layer shine material wanda yake haɓaka heat transfer a kan faduwa da harsuna.

Diagram na differential temperature thermopile

    T1
    |\
    | \
    |  \
    |   \
    |    \
    |     \  ΔV
    |      \
    |       \
    |        \
    |         \
    |          \
    |           \
    |            \
    |             \
    |              \
    |               \
    ------------------
        Thermal
       Resistance
        Layer
    ------------------
    |               /
    |              /
    |             /
    |            /
    |           /
    |          /
    |         /
    |        /
    |       /
    |      /  ΔV
    |     /
    |    /
    |   /
    |  /
    | /
    |/ 
   T2

Thermopiles za su iya yanayi da adadin pairs na thermocouple masu yawan ɗaya don tara voltage output.

Thermopiles za su iya kofar kafin kafin, amma wannan configuration yana da ɗaya ce saboda yana tara current output ba voltage output ba.

Thermopiles ba su iya taimaka da absolute temperature, amma musamman da temperature differences ko gradients.

Saboda haka, za su iya amfani da su don ci heat flux, wanda yana nufin rate of heat transfer per unit area. Heat flux za su iya tafiye ta ziyarta voltage output da thermal resistance da area na device.

Thermopiles sun amfani da infrared radiation don heat transfer da kuma sun amfani don non-contact temperature measurement.

Infrared radiation shine electromagnetic radiation da wavelengths bayan 700 nm to 1 mm, wanda yana neman da temperatures bayan 300 K to 5000 K. Infrared radiation yana faru da object da takawa da nonzero temperature da za su iya tabbatar da ita a cikin thermopile sensor.

Abubuwan Thermopile Sensors

Thermopile sensor shine device wanda yake amfani da one or more thermopiles don ci gadi ko infrared radiation daga object ko source.

Thermopile sensors suna da principles na non-contact measurement da suke da abubuwan faɗiwa da sensors na contact-based, kamar accuracy masu yawa, response time mai gaskiya, range masu yawan, da kuma maintenance mai lili.

Akwai abubuwan thermopile sensors, depending on the number, configuration, and material of the thermocouples, as well as the design of the infrared absorber and the filter. Some of the common types of thermopile sensors are:

• Single-element thermopile sensor: Wani wani na sensors shine da thermopile gaba daya da hot junction gaba daya da cold junction gaba daya. Hot junction shine fitowa a thin infrared absorber, usually a micro-machined membrane on a silicon chip. Cold junction shine fitowa a heat sink ko reference temperature. Sensor yana ci gadi temperature difference a kan hot da cold junctions, wanda yana iya zama da infrared radiation absorbed by the membrane. Wani wani na sensors yana da ma'ana don ci low to medium infrared radiation levels da kuma fast response time.

• Multi-element thermopile sensor: Wani wani na sensors shine da thermopiles goma sha'awa arranged in parallel or in series. Each thermopile shine da hot da cold junctions, wanda suka fitowa a common infrared absorber da common heat sink. Sensor yana ci gadi sum of the voltage outputs from each thermopile, wanda yana iya zama da total infrared radiation absorbed by the membrane. Wani wani na sensors yana da ma'ana don ci high infrared radiation levels da kuma high sensitivity.

• Array thermopile sensor: Wani wani na sensors shine da array of thermopiles arranged in rows and columns on a substrate. Each thermopile shine da hot da cold junctions, wanda suka fitowa a individual infrared absorbers da heat sinks. Sensor yana ci gadi voltage output from each thermopile separately, wanda yana iya zama da local infrared radiation absorbed by each absorber. Wani wani na sensors zai iya create a two-dimensional image of the infrared radiation distribution and can detect the position, shape, and movement of an object.

• Pyroelectric thermopile sensor: Wani wani na sensors shine da pyroelectric material with a thermopile. Pyroelectric material shine material wanda yake faru electric charge idan an baka da jiki ko harsuna. Pyroelectric material shine fitowa a hot junctions of the thermopiles, amma cold junctions suka fitowa a heat sink. Sensor yana ci gadi voltage output from the thermopiles plus the charge output from the pyroelectric material, wanda yana iya z