ISL29501 accuracy


I am considering the ISL29501 in an application to measure water depth.

I would like to know what typical distance measurement accuracy can be achieved with the ISL29501 ?
It does not say anything about the accuracy in the ISL29501 data sheet.

I guess this is highly dependent on particular components used, but still I would like to know what is typical accuracy can be obtained, say using IR, VIS or UV emitters and detectors.

 (Note in a previous forum question ("ISL29501 EVkit incorrect ranging"), the Renesas reply mentioned that a typical setup gave accuracy of +/- 10cm over 2m range. This is only 10% accuracy, which is quite poor.

Can you let me know if this is typical accuracy ?

What sort of accuracy can be achieved with the ISL29501 ?



  • Hello,

    The accuracy of the ISL29501 sensor for distance measurement can depend on a variety of factors, including the specific components used, the design of the application circuit, and the environmental conditions in which the sensor is used.

    As you mentioned, the ISL29501 datasheet does not provide information on the accuracy of the sensor for distance measurement. However, the typical accuracy mentioned in the previous forum question you referenced (accuracy of +/- 10cm over 2m range) may be a reasonable estimate for typical accuracy, although this will depend on the specific setup used. MIBridges

    To achieve the best possible accuracy with the ISL29501, it is important to optimize the deMIBridgessign of the application circuit and use high-quality components. Additionally, the environmental conditions in which the sensor is used can also impact its accuracy.

    Ultimately, the best way to determine the accuracy that can be achieved with the ISL29501 in your specific application is to conduct testing and calibration using a controlled setup and appropriate standards for comparison.

  • Hi Gary!

    Thanks for the request. Your request, In Renesas sensor is very valuable to us. Yeah, the accuracy of ISL29501 is depends upon several factors as mentioned in reply. I have a couple of questions regarding your project.

    What is the distance, you need to measure?

    What is the accuracy (looking for in your project)?



  • Hello Raja

    I want to measure distance of minimum 5m.

    I would need an accuracy of better than 1cm over this range (approx 0.2%)

    Can the ISL29501 achieve this with the appropriate components?

    Thanks for your assistance.



  • Hi,

    Thank you for the response. I had discussed with my team regarding your query. They told me that, +/-1cm in air is already difficult at 5m in air.  In water, there is too much absorption and diffraction of light so that much accuracy we cannot achieve by using ISL29501 device. Apart from that, if you have any other query, please feel free to ask.



  • hi raja

    Thanks for the reply, but I have the following comments:

    +/-1cm in air is already difficult at 5m in air

    This is not correct. 

    1cm at 5m is not difficult for a laser meter in air.
    For example: At my local hardware store I can buy a laser distance meter (Bosch BLAZE 165 Ft. Laser Measure) which quotes 2mm accuracy over 50m.

    In water, there is too much absorption and diffraction of light so that much accuracy we cannot achieve by using ISL29501 device

    You misunderstood my reply. I want to use the device for water level measurement, not IN water.
    I want to measure the distance (in air) down to the water surface, so I can calculate the height of the water level.

    The reason I am interested in the ISL29501 is that I can change the detector and the emitter to use different wavelengths, for example, some wavelengths reflect better on water than others.

    From your replies it seems that the ISL29501 can only achieve typically 10cm accuracy over 5m, which is not good performance.

    I will consider some other device.



  • Hi Gary,

    Sorry, I misunderstood your question, yeah, correct in the evaluation kit / board measures quick evaluation of the ISL29501 performance for a 2m (accuracy of +/- 10cm over 2m range) sensing system. Apart from that range of system can be optimized (up to few meters) for different application by connecting external photodiode and Emitter. Correct, by connecting laser you can achieve higher accuracy, but we cannot assure that.