D25 NC Measuring Spices - VIDEO

This video is about measuring spices and other similar applications, using the D25 NC and its optional petri dish accessory.



Measuring Snack Food Using the Compression Ring and Pan Set - VIDEO

This video demonstrates how to use the compression ring and pan for measuring Snack foods on the D25 NC.

Video: https://www.youtube.com/watch?v=EnpLZz2WlgU

A written form of this procedure can be found here:



D25 NC – Unpacking the Instrument


YouTube - https://youtu.be/EgZsrnn08tE

Sprout -  http://sproutvideo.com/videos/a49bdeb71913ecc52c

D25 NC - Power Up


Youtube - https://youtu.be/Lw9DZuNaIL0

Sprout -  http://sproutvideo.com/videos/d49bdeb71913efc25c

D25 NC - standardize


Youtube - https://youtu.be/IgBA1wyHKzg

Sprout - http://sproutvideo.com/videos/7c9bdeb71913e3ccf4

D25 NC- setting distances


Youtube- https://youtu.be/LiBqHhoX5Ks

Sprout - https://hunterlab.vids.io/videos/e89bdeb71616e1cd60/d25-nc-setting-distances-mov

What is Height Compensation ?

Most benchtop color instruments require the sample to be placed flush against the view port when taking a measurement. If the sample is not flush to the port, then the color measurements may change dramatically. The D25NC is unique in that it is a non-contact color measurements with a corrections applied based on the distance from the sensor. A laser is used to monitor the sample's height and adjust the measurement output. 

During manufacturing, the instrument's white calibration tile is measured at various distances from the sensor window. From this, a correction table can be determine to compensate from the changes in distance. 

The white tile is precisely positioned in a range from 3 inches to 4 inches from the sensor window during our manufacturing and QC testing. The measurements are then compared to the values at 3.5 inches and the DE* must be less than 0.2 units. The full range of the sensor is 2.5 to 4.5 inches and the DE* must be less than 1 unit as compared to the 3.5 inch value.

Because the tolerances are small, they must be done with a precision, as any angular change on the glossy tile surface will have an effect on the measured values. 

In real world applications, the improvement of correction will vary depending on several factors including gloss, texture, angle, and translucency of the sample. In general, a flat level matte surface will show less change in measurement with distance than a glossy or irregular shaped sample due to the way that light reflects off the surface of the sample. 

D25 NC Product Brochures

D25 NC Brochure

D25 NC Brochure (Spanish)

D25 NC Brochure (Portuguese)

D25 NC User Manual

D25 NC User Manual


D25 NC Technical Specifications

Technical Specifications

D25 NC System Overview
Comparing Readings between D25NC instruments

Here are the things to check when you have 2 instruments that read differently.

1) Standardize and read the green check tile on both instruments. If they pass, then the sensors are operating correctly.

2) Check that you have selected the same color scale and illuminant/observer for both instruments. This is typically CIE Lab or Hunter Lab and D65/10 or C/2. They must match on both instruments

3) Make sure you are presenting the samples at the same height and in the same manner of placement. The distance is given with the reading or you can go to Diagnostics/Distance sensor to read the distance from the sensor to the sample being measured. Both samples need to be arranged the same way, whether poured, stacked, or crushed. 

4) Check that the measurements are at the same location on the samples, This is determined by the location of the sensor over the sample. Use the horizontal arm to adjust the white spot from the center to the outside of the sample pan and set it is the same position for both. The white spot is the measurement area, and the red spot is the height measurement. 

Turning On/Off Green Tile Check When Performing Standardization

The requirement of an operator to perform a green tile check as part of sensor standardization can be selected from the SYSTEM SETTINGS/DIAGNOSTIC/ STDZ CHECK menu. The default value is NO (Green tile check is not performed), and can be changed to YES if required (Green Tile Check is included in Standardization).


STDZ CHECK = NO - Only the Black and White Tile are used during Standardization


STDZ CHECK = YES - Black, White, and Green Tile are used during Standardization.


D25NC Distance does not Change for different Height samples


I have a D25 NC serial number 251513. The distance measurement seems to be stuck at 90mm when reading a sample. I have run the diagnostics >distance Sensor check, and the distance does change if different height samples are presented, however when a normal reading is performed, it always states the distance at 90mm.


In the Global Options for the sensor scroll to the Measure Settings. The choices are Fixed or Auto. Based on your description the setting must be Fixed, with a setting of 90mm. If you change the selection to Auto, distance correction will be applied based on the actual measured distance.

Troubleshooting EasyMatch QC Connections to D25NC

Here are 5 common items to check when experiencing issues connecting a D25NC to EasyMatch QC. Please see the attachments for more details.

1) Are you using the latest version of EasyMatch QC V 4.83 or above?
2) Did you select Sensor/D25 Product Setup and fill in the required fields?
3) Is there a switch on the back of the base that has a computer and printer icon (picture) ? Make sure it is switched to computer.
4) Is the system showing up in the computer control panel when you connect USB?
5) Is USB starting and stopping (beeping sound or disappearing in Control Panel)? Turn off USB Power savings in Root Hub of Device Manager USB Controllers Properties

D25NC Distance and Height Modes

There are 2 modes that the sensor can be measure; Distance and Product Height. They are quite different, and set in the Global Options. Along with these modes, there are variables that must be set for the Min and Max to measure when in each mode:




1) Distance: When Distance mode is selected, then the output on the screen displays "Distance" and the value is the measurement from the sensor window to the top of the product (where the laser is hitting). This has a physical operational range of 65 mm to 155 mm. You can restrict the range by using the Min and Max setting in the product setup. For example, if you would like to restrict the measurements between 80 and 100 mm, then you would enter a Min value of 80 and a max value of 100. Anything outside that range will be ignored in the color measurement.




2) Height: When Height mode is selected, the output on the screen will display "Height" and the value is the measurement from the user entered Belt or Background distance and the top of the product (where the laser is hitting). This has a physical operating range of 0- 90 mm. You MUST enter a Belt or Background distance that represents the distance to the bottom of the product or the bottom of the sample tray. For example, if the product you wish to measure has a 10 mm thickness, then the sensor head should be adjusted until the product surface is 90 mm from the sensor window, and the background/Belt should be set to 100 mm. You may then select a minimum height, and a maximum height to restrict the measurement range. Please see the user manual for more information.




There is also a diagnostic feature called "Distance Sensor". This always gives the distance measurement (as above) and is used when initially setting up the sensor head to 90 mm above the product. Please note that not all surfaces can be accurately measured and there is the limit of a minimum of 65 mm and a maximum of 155 mm. If the product is closer or further from the sensor window than those values, the Distance Sensor will be incorrect.




Please also see the instructions for initially setting up a product in the support site: https://support.hunterlab.com/hc/en-us/articles/212149166-Initial-Setup-of-D25NC

D25NC and STHT Communication Protocols

Windows System | Hardware Devices

Communications Parameters:

When connected to a computer communication can be verified by search the

Human Interface Device tree in Hardware Device settings. Do not look for these in the Comm or USB trees.

Expand the HID tree and then select a branch, right click and use the drop down arrow to select ID.

VID = Vendor ID PID = Product ID

All HunterLab products use VID 1D89

USB Class: Human Interface Device (HID)

HunterLab VID: 1D89 (hex)

SpectraTrend HT PID: 5C7B (hex)

D25 NC PID: 5C03 (hex)

USDA Munsell Frozen French Fry Color Standards

The visual USDA Frozen French Fried Potatoes Grades and Standards come in the form of a printed leaflet that depict a series of seven potato color grades in short, long and crinkle cut forms. It is intended for use in classifying the visual color of frozen French fried potatoes, or other similarly fried products.

Source: Visual USDA French Fry Color Standards

Munsell Color Services

Grand Rapids, MI 49512 USA



Munsell USDA Frozen French Fry Standard - 5

Printed color ranges meet specifications set by USDA for frozen French fry potatoes and run from low 000 to high 4. It comes as a set of 5 identical reproductions come in a folder with instructions for visual evaluation of fry color.

How HunterLab Meets this Application

The HunterLab D25 NC is the best choice for this non-uniform potato application. For color QA of fried products you can use the L* lightness (lower with increased bake level) or YI Yellowness Index metrics (higher with increased bake level) and set your own target values for optimal frying in those metrics.

If you wish to also report the correlated USDA Fry Color grade, here is how best to do it.

  • After draining and cooling close to ambient, layer fires in a 12 inch diameter pan. Try to make them as a single layer with minimal spaces between the fries.
  • Using the Munsell USDA Frozen French Fry Standard - 5, make a visual judgment as to which USDA Fry Color grade most closely matches the color of the fries.
  • Read the sample color using D25 NC set for 2 rotations of 5 seconds. Each rotation will average multiple readings of the fries using a 25 mm area of view.
  • Report L*, a*, b* and Yellowness Index values.
  • Based on a range of French Fry Color samples, including light and dark limits, determine an L* lightness or YI yellowness correlation to the USDA Fry Color Grade and report the grade.