How to measure the intensity of Infra red

[MMorris]

Hi,
Im investigating how infra red is affected in different areas e.g at home, out side, in the dark or in light. To do this i have made a circuit with a photodiode from the company rapid. The problem is that the photodiode is operating as just a switch, saying if the infrared is on or off so i am not able to measure how strong or weak, the beam of infra red is.
At the moment, I am thinking of having a phototransisor or infrared transistor to measure the intensity insead of a photodiode but am not sure if it will work with infra red? can anyone help?

Thanks

Matthew

 

[Redbelly98]

Welcome to PF.

A photodiode can work for this, but it depends on the circuit you use it with. It also depends on what infrared wavelengths you are trying to measure. If the infrared you want to measure is outside the detectable range of the photodiode, then all bets are off.

Can you describe (or better, provide a drawing of) the circuit you have?

Regards,

Mark

p.s. Is this for a class assignment or homework? If not, I can inquire about getting the question moved to a more appropriate area here at PF.

 

[baba89]

As a scientist, there are a few different methods you could use to measure the intensity of infrared (IR) light. One option is to use a spectrometer, which is a device that measures the intensity of different wavelengths of light. This would allow you to specifically measure the intensity of IR light in different areas.

Another option is to use a pyroelectric sensor, which can detect changes in heat and convert it into an electrical signal. Since IR light is a form of heat, this type of sensor could be used to measure its intensity.

Using a phototransistor or IR transistor could also work, as they are designed to detect light in the IR spectrum. However, it is important to make sure that the specific sensor you choose is sensitive to the wavelengths of IR light you are trying to measure.

It may also be helpful to calibrate your sensor by comparing its readings to a known IR light source, such as an IR laser or a blackbody radiator.

Overall, the key is to choose a sensor that is specifically designed to detect IR light and ensure that it is properly calibrated for accurate measurements. I hope this helps and good luck with your investigation!