One of the new ways of checking the temperature with thermometer , which uses resistance - send an item. Electric sensor can be made of the thermistor. A thermistor is a piece of material that changes the resistance quickly when exposed to temperature changes. When heated thermistor reduces its resistance. This decrease in resistance makes the scheme of an increase in current. A meter can be inserted in the circuit. Changes in the current can be calibrated standard thermometer. Scales can be marked to read temperature in Celsius or Fahrenheit.
Another type of resistance thermometer shows the temperature with led indicator. Resistance sensitive lamp is placed in the liquid. The bridge circuit is adjusted until the led lights up. The valve which regulates the bridge circuit is measured in degrees Celsius or degrees Fahrenheit. The handle then shows temperature. The sensor element is just one of the resistors in the chain bridge.
There is a possibility of a practical accuracy 1F (0.5C).
In this type of measurement, the range covered by this -325 250F (-198 121C). Block can be used for deep freezing testing for air conditioning units and for other work. Answer quick. Special bulbs available for use indoors, outdoors, immersion in water, on the surface, and in the ducts.