What is the Threshold Value (250) in LM35 temperature sensor

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1

In the Temperature Alert Project(uses LM35 sensor), what is the threshold value (250) given by us and how to convert it to degree Celcius?

2

Use the formula T=r/10.24, here ā€˜Tā€™ is Temperature in Celsius, ā€˜rā€™ is Analog Pin Reading from Bolt. Hence by using this you will get the required Temperature reading in celsius. Also your thresold value 250 is T(thresold) = 250/10.24 = 24.414 C.

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3

For every +1 Celsius rise in temperature there will be +10mV higher voltage at the output pin. So if the temperature is 0ā—¦ Celsius the output of sensor will be 0V, if the temperature is 10ā—¦Celsius the output of sensor will be +100mV, if the temperature is 25ā—¦Celsius the output of sensor will be +250mV.

So we are using 250 as the threshold Value which is 25ā—¦ Celsius.
We can Calculate it by using the formula given below,

                      T=r/10.24

here ā€˜Tā€™ is Temperature in Celsius, ā€˜rā€™ is Analog Pin Reading from Bolt

Threshold value 250 is calculated as
T(threshold) = 250/10.24 = 24.414 ā—¦C which is 25 ā—¦C approx.

4

V OUT =+1,500 mV at +150ĖšC
= +250 mV at +25ĖšC
= āˆ’550 mV at āˆ’55ĖšC

5

The threshold value is given so that we can generate an alert after temperature crosses that particular value.You can convert the analog pin values into celsius by using this formula T=r/10.24.Here we use A0 as the voltage increases with temperature and relation between volatage temperature is:
per 1 degree rise in temperature the voltage increases by 10mV.
The threshold value 250 in terms of mV can be converted into celsius as shown below:
T(in celsius)=r/10.24
T(in celsius)=250/10.24
T(in celsius)=24.485

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6

In the Temperature Alert Project using the LM35 sensor, the threshold value of 250 refers to the analog output value from the LM35 sensor at a certain temperature level.
To convert this value to degrees Celsius, you can use the formula: temperature in Celsius = (analog output value ) / 10.24.
For example, if the analog output value is 250, the temperature in Celsius would be (250 / 10.24 )ā‰ˆ 25Ā°C.

7

Temperature in Celsius = ( SensorValue / 10) = (250 / 10) = 25 degrees Celsius

So, the threshold value of 250 corresponds to a temperature of 25 degrees Celsius .

The LM35 temperature sensor is a precision integrated circuit sensor that provides an analog output voltage linearly proportional to the Celsius temperature. The output voltage of the LM35 sensor increases by 10mV for every degree Celsius rise in temperature.

8

The threshold value of 250 in the Temperature Alert Project, which uses an LM35 temperature sensor, is typically a raw analog voltage reading from the LM35 sensor. To convert this threshold value to degrees Celsius, you can use the following formula:

Temperature in Celsius = (Threshold Value / 10.24)

The LM35 sensor provides an output voltage of 10.24 mV per degree Celsius. So, by dividing the threshold value by 10.24, you convert it to the corresponding temperature in degrees Celsius.

For example, if your threshold value is 250, then the corresponding temperature in degrees Celsius would be:

Temperature = (250 / 10.24) ā‰ˆ 25 degrees Celsius
So, a threshold value of 250 corresponds to a temperature of 25 degrees Celsius in this project.

9

T=r/10.24(formula) , 250- ā€œTā€( threshold) here r is the analog pin reading
T=250/10.24
T=24.41C

10

The threshold value of 250 refers to the analog output value from the LM35 sensor at a certain temperature level.

11

In the context of an LM35 temperature sensor, the threshold value of 250 usually refers to a scaling factor used to convert the sensorā€™s analog output voltage to temperature in degrees Celsius (Ā°C). The LM35 is a temperature sensor that provides an analog voltage output proportional to the temperature it measures.

Hereā€™s how the conversion works:

  1. The LM35 sensor outputs a voltage that is linearly proportional to the temperature it senses. Specifically, it produces 10 mV (0.01 volts) per degree Celsius of temperature change. This means that for every 1Ā°C change in temperature, the output voltage changes by 0.01 V.

  2. To convert the LM35ā€™s analog output voltage to temperature in Ā°C, you can use the following formula:

    Temperature (in Ā°C) = (Analog Voltage Output - 0.5 V) / 0.01 V

    The subtraction of 0.5 V is typically done to account for the sensorā€™s offset voltage.

  3. If you have a threshold value of 250 mentioned, it may be referring to a specific voltage level used as a threshold for some application or circuit. For example, if you want to trigger an event or take some action when the temperature reaches a certain threshold (e.g., 25Ā°C), you would compare the converted analog voltage to this threshold value.

In this case, if the threshold value is 250, it would correspond to a temperature of 25Ā°C because 250 mV (0.25 V) / 0.01 V per Ā°C = 25Ā°C.

Please note that the threshold value may vary depending on the specific application or circuit where the LM35 sensor is used. You can set the threshold value to suit your particular needs or project requirements.

12

In the Temperature Alert Project that uses an LM35 sensor, the threshold value of 250 is most likely a value in analog units representing the temperature reading from the LM35 sensor. To convert this value to degrees Celsius, you need to use the sensorā€™s datasheet or specifications.

The LM35 is a temperature sensor that provides a linear analog voltage output proportional to the temperature in degrees Celsius. It typically has a sensitivity of 10 mV per degree Celsius. This means that for every 1 degree Celsius change in temperature, the output voltage of the LM35 changes by 10 mV.

To convert the sensor reading (in analog units) to degrees Celsius, you can use the following formula:

Temperature (in degrees Celsius) = (Analog Reading / 10) - 50

In this formula, ā€œAnalog Readingā€ represents the value you read from the LM35 sensor. So, to convert your threshold value of 250 to degrees Celsius:

Temperature (in degrees Celsius) = (250 / 10) - 50 = 25 - 50 = -25 degrees Celsius

So, a threshold value of 250 from the LM35 sensor corresponds to -25 degrees Celsius. You can adjust your threshold value accordingly based on your desired temperature alert threshold in degrees Celsius.

13

In the context of a Temperature Alert Project that uses an LM35 sensor, the threshold value of 250 is likely a reference value that you have chosen for temperature comparison. LM35 is an analog temperature sensor that outputs a voltage linearly proportional to the temperature in degrees Celsius.

To convert the threshold value of 250 to degrees Celsius, you need to understand the sensorā€™s voltage-to-temperature relationship. The LM35 datasheet specifies that it has a temperature coefficient of 10 mV per degree Celsius. This means that for every 1 degree Celsius change in temperature, the output voltage of the LM35 changes by 10 mV.

To convert the threshold value (in millivolts) to degrees Celsius, you can use the following formula:

Temperature (in Ā°C) = (Threshold Value in mV / 10)

In your case, with a threshold value of 250 mV, the temperature in degrees Celsius would be:

Temperature (in Ā°C) = (250 mV / 10) = 25Ā°C

So, the threshold value of 250 corresponds to 25 degrees Celsius. This means that when the LM35 sensor output voltage reaches 250 mV, it indicates a temperature of 25Ā°C, and this threshold can be used in your project for temperature alert purposes.

14

The LM35 sensor provides a linear output voltage that is proportional to the temperature in degrees Celsius. Typically, the LM35 provides 10 mV per degree Celsius change in temperature. Therefore, you can use this formula to convert the raw sensor value (in millivolts) to degrees Celsius:

Temperature (in Celsius) = (Raw Value / 10)

So, if you have a raw value of 250, you can convert it to degrees Celsius as follows:

Temperature (in Celsius) = (250 / 10) = 25 degrees Celsius

Therefore, in this case, a raw sensor value of 250 corresponds to a temperature of 25 degrees Celsius. You can adjust the threshold value accordingly based on your projectā€™s requirements.

15

Hi @dagdih
The threshold value of 250 in a Temperature Alert Project using an LM35 sensor likely refers to a raw voltage reading, not a temperature in degrees Celsius.

The LM35 sensor itself outputs a voltage directly proportional to the temperature itā€™s measuring. This voltage increases by 10 millivolts
(mV) for every degree Celsius rise in temperature.
You can convert the value read by the sensor directly temperature in degrees by multiplying it with 0.1

16

The threshold value is given so that we can generate an alert after temperature crosses that particular value.You can convert the analog pin values into celsius by using this formula T=r/10.24.Here we use A0 as the voltage increases with temperature and relation between volatage temperature is:
per 1 degree rise in temperature the voltage increases by 10mV.
The threshold value 250 in terms of mV can be converted into celsius as shown below:
T(in celsius)=r/10.24
T(in celsius)=250/10.24
T(in celsius)=24.485
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