NIR device calibration

Calibration of the Felix Produce Quality Meters (NIR devices) to move to a fee-for-service arrangement

Over the past 5 years, AMIA in collaboration with Central Queensland University (CQU) has been conducting the calibration of all NIR devices used in the mango industry. This activity has been undertaken by AMIA’s Industry Development Officers and supported by funding from Hort Innovation. Due to an increasing amount of devices requiring calibration and the Hort Innovation funding coming to an end, calibrations of the NIR devices are required to transition to a fee-for-service as of the 2023-24 season.

How are NIR devices calibrated and why is it important?

The Felix Produce Quality Meter uses near-infrared (NIR) spectroscopy to estimate dry matter. Working like a high-powered flashlight, the device sends particles of light into the mango, then measures the NIR light interactance with molecular components inside of the mango to quantify the dry matter.

NIR spectroscopy is an indirect analytical technique which requires calibration. Given that each Felix machine has a unique spectrometer and every mango season is different, each NIR unit should be calibrated every year to take into account the seasonal variability.

Calibration is performed by predicting the dry matter content of a set of fruit samples with each NIR device, and comparing these predictions with the actual dry matter obtained by performing the destructive dry matter assessment on the same pieces of fruit.

How to get your NIR device calibrated this season

This season, calibrations of both F-750 and F-751 devices will be conducted in Darwin by the NT/WA IDO in collaboration with CQU. The timing of calibrations will be dependent on fruit availability and will be communicated closer to the season’s start (likely mid to late August).

If you would like AMIA to calibrate your device, please find the calibration fee below:

Cost per device: $400 + GST

Alternatively, instructions for unit owners wishing to perform their own calibration in-house are available below, but please note it requires access to specific equipment for accurate calibration.

Instructions to calibrate your NIR device in-house

Near Infrared Spectroscopy (NIRS) provides a rapid and non-destructive means to predict mango dry matter which, in turn, can be used as an indicator of fruit maturity and eating quality. NIRS is an indirect analytical technique which requires calibration.

Each NIR device includes custom-built models based on the machine’s performance over the previous seasons. A well performing model will provide a good correlation between NIR dry matter prediction and the actual dry matter content. However, because every season is different, it is common to see a seasonal bias unique to each device, which needs to be corrected every year.

This method will assist in correcting the instrument’s seasonal bias, as well as assessing the performance of the model in use.


A spreadsheet template has been developed to include the calculations for dry matter and statistical parameters. Due to the file format, access will need to be requested via the button below: 

Spreadsheet Template

Once you have access to the spreadsheet template (via Google Drive), you can download it on your computer to add in your data. If you have any issue accessing the spreadsheet template, or have further questions regarding the NIR calibration methodology, please contact the AMIA team.

Reminder: Upgrading your F750

AMIA would like to remind F-750 unit owners that there is a more up to date firmware version, which works with apps rather than models, with improved useability and higher performance. Most of the older F-750 units will require a hardware upgrade to handle the new firmware. To update the hardware, the F750 must be sent back to Felix Instruments in the United States (US) and involves additional costs.

AMIA will continue to provide a calibration service for both older and upgraded F-750 for at least the 2023-24 season, but support for ‘legacy’ units requires extra work and time for troubleshooting and may be withdrawn in the future.

If you have any question regarding the F-750 upgrade or would like to get your unit upgraded, please get in touch with the AMIA team.

Back to Top