One last question. What is the temperature of the sensor when you are getting those readings (read: 48843 Temperature: 2.64975 °C)? Presumably it's ambient, so you are expecting to see about 20 °C?
It's possible that the sensor needs to be characterised. Based on what I have read there are a couple of important parameters that go into the equations so that you get the correct values for this sensor. You can use general values, but if you have specific values for your sensor then it will be more accurate.
First, you need to know the actual resistance of the tiny resistor on board. It is marked "103", which is 10k ohms. But your resistor might not be precisely that value. Next, you need to measure the resistance of the thermistor at various temperatures (actually, two is enough) to calculate the Beta of your sensor. All the cool kids use this one: https://www.thinksrs.com/downloads/prog ... ulator.htm
Enter the resistance at T1 and T2. The thermistor should be 10k at 25 °C. The value given for Beta on the product website is 3950, but yours might be different. You could add an additional temperature reading and calculate your Steinhart-Hart coefficients for your sensor.
Next, double-check the maths that are used in the code. There is a simple formula using Beta, or another one using Steinhart-Hart which you can use to go from an ADC value to temperature.
Actually, in your first message the Arduino link uses a Steinhart-Hart calculation. The second link uses Beta.
Anyway, check the value of the on-board resistor, and measure the resistance of the sensor at various temperatures. The SRS website recommends one value close to each end of the operating range, and one in the middle. Post them here, and use them to calculate your Beta value and Steinhart-Hart coefficients.
It's possible that the sensor needs to be characterised. Based on what I have read there are a couple of important parameters that go into the equations so that you get the correct values for this sensor. You can use general values, but if you have specific values for your sensor then it will be more accurate.
First, you need to know the actual resistance of the tiny resistor on board. It is marked "103", which is 10k ohms. But your resistor might not be precisely that value. Next, you need to measure the resistance of the thermistor at various temperatures (actually, two is enough) to calculate the Beta of your sensor. All the cool kids use this one: https://www.thinksrs.com/downloads/prog ... ulator.htm
Enter the resistance at T1 and T2. The thermistor should be 10k at 25 °C. The value given for Beta on the product website is 3950, but yours might be different. You could add an additional temperature reading and calculate your Steinhart-Hart coefficients for your sensor.
Next, double-check the maths that are used in the code. There is a simple formula using Beta, or another one using Steinhart-Hart which you can use to go from an ADC value to temperature.
Actually, in your first message the Arduino link uses a Steinhart-Hart calculation. The second link uses Beta.
Anyway, check the value of the on-board resistor, and measure the resistance of the sensor at various temperatures. The SRS website recommends one value close to each end of the operating range, and one in the middle. Post them here, and use them to calculate your Beta value and Steinhart-Hart coefficients.
Statistics: Posted by ame — Tue Oct 29, 2024 6:56 am