WHY IS IT IMPORTANT TO MEASURE TEMPERATURE?

REQUIRES THE SENSOR TO BE IN DIRECT OR PHYSICAL CONTACT WITH THE

MEDIA OR OBJECT BEING SENSED. IT CAN BE USED TO MONITOR THE TEMPERATURE OF SOLIDS, LIQUIDS OR GASES OVER AN EXTREMELY WIDE

TEMPERATURE RANGE.

MEASUREMENT INTERPRETS THE RADIANT ENERGY OF A HEAT SOURCE IN THE

FORM OF ENERGY EMITTED IN THE INFRARED PORTION OF THE ELECTROMAGNETIC SPECTRUM.

TEMPERATURE SENSOR COMPRISE THREE

FAMILIES

TWO DIFFERENT METAL BONDED TOGETHER UNDER HEAT AND PRESSURE

TO FORM A SINGLE STRIP OF MATERIAL. BY EMPLOYING THE DIFFERENT EXPANSION RATES OF THE TWO MATERIALS, THERMAL ENERGY CAN BE CONVERTED INTO ELECTRO-MECHANICAL MOTION.

TWO BASIC BI-METAL THERMOSTAT TECHNOLOGIES

USES A FORMED BI-METAL DISC TO PROVIDE A NEAR INSTANTANEOUS

CHANGE OF STATE (OPEN TO CLOSE AND CLOSE TO OPEN)

USES A BI-METAL STRIP TO SLOWLY OPEN OR SLOWLY CLOSE THE CONTACTS. THE OPENING SPEED IS DETERMINED BY THE BI-METAL SELECTED AND THE RATE OF TEMPERATURE CHANGE OF THE APPLICATION

USE EXPANDING LIQUID TO OPEN OR CLOSE CONTACTS IN RESPONSE TO

TEMPERATURE CHANGES.

MAKES USE OF BULK ELECTRICAL RESISTANCE PROPERTIES OF SEMICONDUCTOR MATERIALS, RATHER THAN THE JUNCTION OF TWO DIFFERENTLY DOPES AREAS

ALL OBJECTS EMIT INFRARED ENERGY PROVIDED THEIR TEMPERATURE

IS ABOVE ABSOLUTE ZERO (0 KELVIN). THERE IS A DIRECT CORRELATION BETWEEN THE INFRARED

ARE FORMED WHEN TWO ELECTRICAL CONDUCTORS OF DISSIMILAR METALS OR ALLOYS ARE JOINED AT ONE END OF A CIRCUIT.

THE CONDUCTORS ARE OUTSIDE THE THERMOCOUPLE SHEATH. THEY HAVE A VERY RAPID RESPONSE TO TEMPERATURE CHANGES BUT CAN BE EASILY DAMAGED. THE BEST USE FOR EXPOSED JUNCTION THERMOCOUPLES IS WHERE A FAST RESPONSE IS REQUIRED, AND THERE IS A LOW RISK OF DAMAGE TO THE SENSOR.

THE CONDUCTORS ARE CONNECTED AND WELDED TO THE EXTERNAL SHEATH, WHICH

FORMS A SEALED CONNECTION. SINCE THE WIRES ARE CONNECTED TO THE SHEATH, THEY ARE NOT INSULATED AND MAY BE AFFECTED BY EMF‘S. THEY ARE USED TO MEASURE TEMPERATURES IN CORROSIVE ENVIRONMENTS AND ARE THE MOST COMMON FORM OF CONNECTION.

JUNCTION USES MAGNESIUM OXIDE INSULATING MATERIAL, TO PROTECT THE SENSOR FROM EMF‘S. THE RESPONSE TIME OF AN UNGROUNDED THERMOCOUPLE IS SLOWER THAN A GROUNDED OR EXPOSED JUNCTION TYPES. THEY ARE USED TO PROTECT SENSITIVE ELECTRONICS FROM FEEDBACK VOLTAGES.

TYPE OF THERMOCOUPLE IS FORMED WITH IRON AND CONSTANTAN. -210 TO 760 °C IS ITS TEMPERATURE RANGE. OWING TO THE LOW-TEMPERATURE RANGE OF THE THERMOCOUPLE, ITS LIFE SPAN REDUCES IN HIGH TEMPERATURES.

CHROMEL AND ALUMEL FORM A _TYPE THERMOCOUPLE. THE TEMPERATURE RANGE IS BETWEEN -270 AND 1372 °C. THE NEUTRAL OR OXIDIZING ENVIRONMENT IS BEST SUITED FOR THESE TYPES OF THE THERMOCOUPLE.

IT IS FORMED WITH COPPER AND CONSTANTAN. THE TEMPERATURE RANGE IS BETWEEN -270 TO 400° C. THIS TYPE OF THERMOCOUPLE IS SUITABLE FOR THE INERT ATMOSPHERE AS WELL AS THE VACUUM.

CHROMEL AND CONSTANTAN ARE THE ALLOYS THAT FORM AN _TYPE THERMOCOUPLE. THE TEMPERATURE RANGE IS BETWEEN -270 TO 1000 °C. THIS THERMOCOUPLE DOES NOT FOCUS ON THE OXIDATION IN THE ATMOSPHERE AND CAN BE USED IN AN INERT ENVIRONMENT.

THIS THERMOCOUPLE IS A COMBINATION OF ALLOYS NICROSIL AND NISIL. THE TEMPERATURE RANGE IS BETWEEN -270 TO 1300 °C. UNLIKE K-TYPE THERMOCOUPLES, OFFERS VERY HIGH RESISTANCE FOR DEGRADATION DUE TO GREEN ROT AND HYSTERESIS.

A COMBINATION OF PLATINUM (13% RHODIUM) AND PLATINUM FORMS R TYPE THERMOCOUPLE. THE TEMPERATURE RANGE IS BETWEEN -50 TO 1768 °C.

IT IS A COMBINATION OF PLATINUM (10% RHODIUM) AND PLATINUM. THE TEMPERATURE RANGE IS BETWEEN -50 TO 1768 °C.

THE ALLOY COMBINATION IS OF PLATINUM (6% RHODIUM) AND PLATINUM (30% RHODIUM). THIS THERMOCOUPLE EXHIBITS A TEMPERATURE RANGE BETWEEN 0 TO 1820 °C.

CAN BE CHECKED IN ANY PHASE OF PRODUCTION. THERMOCOUPLES ARE A TWO PIECE UNIT WITH A HANDHELD READOUT UNIT AND DETACHABLE

PROBE.

REQUIRE HIGH TEMPERATURE AND PRESSURE. THE SENSOR TIP HAS TO BE

POSITIONED IN THE MOLTEN PLASTIC UNDER HIGH PRESSURE CONDITIONS.

THE THERMOCOUPLE SHUTS OFF THE GAS SUPPLY WHEN IT DOES NOT SENSE A FLAME AND PREVENTS THE FURNACE FROM RECEIVING GAS WHEN THE PILOT IS OUT.

SIGNALS THE GAS VALVE THAT THE PILOT IS LIT SO

IT WILL REMAIN OPEN. THE THERMOCOUPLE IS POSITIONED IN THE MIDDLE OF THE PILOT

FLAME. IT DETECTS THE HEAT OF THE FLAME AND GENERATES THE VOLTAGE THAT KEEPS THE

GAS FLOWING.

ARE FORMED WHEN TWO ELECTRICAL CONDUCTORS OF DISSIMILAR METALS OR

ALLOYS ARE JOINED AT ONE END OF A CIRCUIT. THERMOCOUPLES DO NOT HAVE SENSING ELEMENTS, SO THEY ARE LESS LIMITED THAN RESISTIVE TEMPERATURE DEVICES (RTDS) IN TERMS OF MATERIALS USED AND CAN HANDLE MUCH HIGHER TEMPERATURES. TYPICALLY, THEY ARE BUILT AROUND

RTD) IS AN ELECTRONIC DEVICE USED TO DETERMINE THE TEMPERATURE BY MEASURING THE RESISTANCE OF AN ELECTRICAL WIRE. THIS WIRE IS REFERRED TO AS A TEMPERATURE SENSOR.

USE A THIN FILM OF METAL ON A SUBSTRATE AS THE SENSING

ELEMENT. THE METAL USED IN THE THIN FILM IS TYPICALLY PLATINUM

IS A TYPE OF TEMPERATURE SENSOR THAT USES A WIRE MADE OF A SPECIFIC METAL (USUALLY PLATINUM, NICKEL, OR COPPER) WOUND AROUND A CERAMIC OR GLASS CORE.

CONSIST OF A WIRE COIL MADE OF A MATERIAL WITH A KNOWN TEMPERATURE COEFFICIENT OF RESISTANCE, SUCH AS PLATINUM OR NICKEL. AS THE TEMPERATURE OF THE COIL CHANGES, SO DOES ITS RESISTANCE, AND THIS CHANGE IN RESISTANCE CAN BE MEASURED AND USED TO DETERMINE THE TEMPERATURE.

REFERS TO A SPECIFIC TYPE OF RTD SENSOR THAT USES PLATINUM AS THE SENSING ELEMENT.

REFERS TO THE PLATINUM MATERIAL USED IN THE SENSOR, WHICH HAS A RESISTANCE OF 1000 OHMS AT 0°C.

CONSISTS OF TWO WIRES CONNECTED TO THE RESISTANCE ELEMENT.

THESE TWO WIRES ARE USED BOTH FOR SUPPLYING POWER TO THE RTD

AND FOR MEASURING THE RESISTANCE OF THE ELEMENT.

THERE ARE THREE WIRES CONNECTING THE RTD ELEMENT TO THE MEASURING

INSTRUMENT OR CONTROL SYSTEM. TWO OF THESE WIRES CARRY A CONSTANT CURRENT, AND THE THIRD WIRE IS USED TO MEASURE THE VOLTAGE DROP ACROSS THE RTD ELEMENT.

IT HAS FOUR WIRES CONNECTED TO IT, TWO FOR CARRYING A CONSTANT CURRENT

AND TWO FOR MEASURING THE VOLTAGE ACROSS THE RTD.

A THERMALLY SENSITIVE RESISTOR THAT EXHIBITS A PRECISE AND PREDICTABLE CHANGE IN

RESISTANCE PROPORTIONAL TO SMALL CHANGES IN BODY TEMPERATURE. RESISTANCE THERMOMETER OR AN INSTRUMENT SUCH AS A RESISTOR WHOSE RESISTANCE IS BASED ON TEMPERATURE. THE TERM IS A COMPOSITION OF “RESISTOR” AND “THERMAL”

ARE RESISTORS WITH A POSITIVE TEMPERATURE COEFFICIENT, WHICH MEANS THAT

THE RESISTANCE INCREASES WITH INCREASING TEMPERATURE.

REFERS TO THE RESISTANCE CHANGE BASED ON THE TEMPERATURE

CHANGE.