The lm35 series devices are available packaged in hermetic to transistor packages while the lm35c lm35ca and lm35d devices are available in the plastic to 92 transistor package. Avr microcontroller based digital thermometer using lm35 in this project we are going to design a circuit for measuring temperature. The lm35 provides 10mvc degrees and considering that the resolution for human temperature is normally assessed in the range of 01c degrees this means that the noise expected should not exceed 1mv. The output voltage rises by 10mv for every 1 degree celsius rise in temperature. Lm35 celsiuscentigrade resolution is 10 mills volt. Heart beat sensor was used for sensing heart rate.
The arduino stores this as a 10bit number 0 1023. Measure temperature using lm35 and arduino. It can measure temperature from 55 degree celsius to 150 degree celsius. The voltage output of the lm35 increases 10mv per degree celsius rise in temperature. The lm35 is an analog linear temperature sensor. The arduino can read input from 0 5v.
So if lm35 outputs 100 mills volts the equivalent temperature in centigradecelsius will be 10010 10 centigradecelsius. Body temperature is a basic parameter for monitoring and diagnosing human health. Temperature is usually measured in centigrade or faraheite. The lm35 device is rated to operate over a 55c to 150c temperature range while the lm35c device is rated for a 40c to 110c range 10 with improved accuracy. Lm35 can measure from 50 degree centigradecelsius up to 150 degree centigradecelsius. Body temperature measurement using lm35 i still find some drawbacks on using analog sensors for remote sensing for that application unless cabling is properly shielded and twisted.
The lm35 provides 10mvc degrees and considering that the resolution for human temperature is normally assessed in the range of 01c degrees this means that the noise expected should not exceed 1mv. Lm35 can be operated from a 5v supply and the stand by current is less than 60ua. Lm35 is used for the sense body temperature. This means that the output voltage is proportional to the temperature. 10 mills volt represent one degree centigradecelsius. As a temperature sensor the circuit will read the temperature of the surrounding environment and relay thi temperature to us back in degrees celsius.
In this project we will demonstrate how to build temperature sensor circuit using a lm35 sensor. This circuit is developed using lm35 a linear voltage sensor. The ic we will use to measure the temperature is the lm35 ic. Lm35 is three terminal linear temperature sensor from national semiconductors.
Gallery of Body Temperature Measurement Using Lm35
