We all are very well aware that thermometer is a medical equipment used to measure body temperature by doing which doctors can recommend the medicine to the patients. Moreover, by frequently measuring the body temperature at the time of fever helps in maintaining the body temperature. Thermometers are used in industries to regulate the various processes, in medicine, in knowing weather conditions and of course for scientific purposes and researches.
Digital Thermometer measures the temperature more precisely as compared to conventional mercury thermometer and digital thermometers do not contain mercury instead these thermometers contain the thermistor inside the tip which do the work of measuring the temperature.
Benefits of using a digital thermometer:
- They are easy to read
- Gives accurate reading
- Can record auxiliary, rectal and oral temperatures
Also, the top of the thermometer is capped as this part is held away from the body. Mainly this cap gives protection to the battery from outer environment.
Working of a digital thermometer depends upon the type of sensor installed in it and different types of sensor are:
- Resistance temperature detectors (RTDs): This sensor changes its resistance with the change in temperature. They work by using the positive temperature coefficient of electrical resistance of metals and generally Platinum metal is used as it maintains the linearity over the wide range of temperature. Also, the value of electrical resistance increases with the increase of temperature.
- Thermocouples: In thermocouples, a pair of metal wires are joined at one end which between their openings produces a net thermoelectric voltage and voltage also depend on the temperature difference at the ends. And, calibration formula is used to read the voltage. This sensor, is highly sensitive even to the small change in the temperature.
- Thermistor: These sensors are smaller in size and are more stable compared to other sensors but they can’t be used in the extreme temperatures and also they are not linear. Basically, thermistor is a semi-conductor device in which electrical resistance is proportional to temperature.
Applications of Digital Thermometer – They are most commonly used for medicinal purposes, in laboratories, food or pharmaceutical applications, meteorological purposes, maintaining temperature on home appliances etc.
Digital Thermometer is a very handy device and can be taken anywhere, moreover, can be easily used by anyone as compared to traditional mercury-based thermometer.