Testing of Sensor

Thread Starter

Anchorite

Joined Aug 25, 2022
5
Hi guys,
I am trying to test the optical heart rate (OHR) sensor, the sensor includes LEDs and PIN photodiodes. I need to test properties of the emitters and detectors. What should I use?
 

KeithWalker

Joined Jul 10, 2017
2,522
Actually, the question said design a test machine to verify the performance of the sensor, I don't know the specific model of the sensor.
If you don't have the specifications of the sensor, you can not test its performance to its specifications. All you can do is check the functionality of anything you know for sure about it.
 

WBahn

Joined Mar 31, 2012
27,418
Actually, the question said design a test machine to verify the performance of the sensor, I don't know the specific model of the sensor.
But what "performance" is it that you are supposed to verify? How can you verify something if you don't know what the something is supposed to be?

Look at a data sheet for a typical LED or photodiode used for that purpose, particularly one from a quality manufacturer. There are likely dozens of performance specifications for all kinds of different parameters, including electrical, optical, thermal, and physical. Is your machine supposed to "verify" that the device meets all of them? If not, which ones? The machine you design to verify absolute electrical specifications is going to be very different than the one you use to verify typical electrical specifications and both will be very different from a machine that deals with one or more of the optical specifications.
 

Jerry-Hat-Trick

Joined Aug 31, 2022
166
I'm thinking you are looking at an SPO2 finger sensor? The attached NXP application note was helpful to me - including the D type connections. This app note is already 10 years old but it describes the fundamentals nicely. In the meantime integrated analog front ends and complete integrated solutions are available but if you are digging into the fundamentals this is a good place to start
 

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