AS7263 Measurements / NIR Light / Consultations

[Manuel_Crisanta]

Hello,

I am using the NIR sensor AS7263 to determine the Brix degree in mandarin juice, and I have a couple of questions.Currently, I am using a white LED light in a closed environment, but I am not sure if this is the right light, as I have noticed significant variations between the measurements taken with this light and those made with ambient light.

1. How should I set up the light to correctly measure reflectance and ensure that the sensor is reading correctly?

2. Is it necessary to use a specific type of light or calibrate the sensor in any way to obtain accurate measurements?Additionally, this sensor has a measurement range of 610 nm to 860 nm, but generally NIR spectra start from 800 nm.

3. Can it be said that this sensor measures both visible and infrared light, given that its range includes wavelengths within visible light (610-750 nm)?

Thank you for your help.

Regards,

[TS-Russell]

Questions the NIR AS7263

Calibrate against your light source in the enclosed area vs the same area un-lit/dark Yes, you’ll want a light source with a small frequency output range…some white LEDs will fit the bill, but you’ll want to ensure its specs are desirable. You can also test with different ones to watch how the data shifts Yep…the only way to mitigate this is calibrating

[jremington]

@Manuel_Crisanta

Can it be said that this sensor measures both visible and infrared light

NIR (Near IR) is loosely defined as light with wavelengths between 750 - 1400 nm, with some variation in those limits, whereas light is generally agreed to be visible to the human eye for wavelengths between around 380 to 750 nm.

The AS7263 sensor crosses that boundary, with three photodiodes responding in the visible region at 610, 680 and 730 nm.

If you are measuring refractive index, which depends on wavelength, ideally you would choose an appropriate narrow band of wavelengths. Brix refractometers often use the sodium D line emission at 589 nm, sample measured at 20 degrees C: Brix - Wikipedia

[Manuel_Crisanta]

1. I use a light source and obtain values as shown in the image. However, without the light, no values are obtained.
   

   

2. Currently, I am using a white LED strip placed over my sample to illuminate it and capture the reflectance values. My question is whether the LED incorporated in the NIR sensor is suitable for my sample, or if it would be more reliable to use another type of light source. Is the LED in this sensor the most appropriate for these types of measurements?

I appreciate your support in obtaining more accurate and reliable measurements.

[jremington]

@Manuel_Crisanta

to determine the Brix degree in mandarin juice

The refractive method I mentioned measures the change in path direction as the light passes through the sample. It has nothing to do with reflected light.

What method are you using to determine the Brix degree? Can you post a link to a description?