Presence and temperature with 1 sensor?

Other Hardware Sensors
1

Hello.

I want to make a circuit that recognizes the presence of an object and that measures the temperature of the object.

For recognizing the presence I found that I can use an infrared sensor like: TCRT5000

And for measuring the temperature I can use infrared sensor: MLX90614

But these are both infrared sensors. So do you guys know if I can do both functions with 1 sensor?
Can I use the MLX90614 for instance also to detect an object in front of it?

Thanks in advance,

Olaf

2

If the object's temperature is always going to be different to the ambient temperature then you can detect its presence by the fact that you're not measuring the temperature of the back wall behind where the object is supposed to be.

If not, maybe you can heat the back wall so you can detect that the object is there when you measure some other temperature.

The optical presence sensor is going to cost less than $2, even in quantity 1, so it's not expensive to have both. I like the QRE1113 but there's a zillion similar sensors for that short range presence detection.

3

MorganS:
If the object's temperature is always going to be different to the ambient temperature then you can detect its presence by the fact that you're not measuring the temperature of the back wall behind where the object is supposed to be.

If not, maybe you can heat the back wall so you can detect that the object is there when you measure some other temperature.

The optical presence sensor is going to cost less than $2, even in quantity 1, so it's not expensive to have both. I like the QRE1113 but there's a zillion similar sensors for that short range presence detection.

Thank you MorganS.

Indeed, it could be possible to use the change in temperature as an indicator of the presence of an object. I will try to program this and buy a sensor like the proposed QRE113 as a backup.

Thank you also for suggesting this sensor, it already has a cleaner look than the TCRT5000.