On-line colour measurent of edible oils


Thread Starter


The measurement of colour for edible oils is done using a tintometer. Comparing the oil colour with several colour slides. Usually measured on a Lovibond scale. I am interested in measuring it on-line and feed it back to a PLC. Does anyone have experience with any instrument that can do this.
I did some work with HunterLab several years ago looking at on-line real time color measurement of biscuits. Try them. They are in Reston, Virginia
in the US.



Johan Bengtsson

How does the color change?
Is it darker/lighter or is it approximately the same darkness but changing between (for instance) a yellow and a green shade?

Anyway, could you just have some kind of light source and a light sensor on opposite sides of the pipe (the pipe will of course have to be made of glass or something similar right there), or a couple of them using different wavelengths if the color changes (as opposed to only darkness).

You would probably want to put all this in a dark box, or have pulsed light transmitters and some "intelligent" reciever igoring changes with the wrong frequency and/or phase.

I don't know if this will work practically in your application but it is an idea at least.

/Johan Bengtsson

P&L, Innovation in training
Box 252, S-281 23 H{ssleholm SWEDEN
Tel: +46 451 49 460, Fax: +46 451 89 833
E-mail: [email protected]
Internet: http://www.pol.se/


Steen Balchen

Dear Andrew,
Did you ever solve your problem? If yes, I would like to hear which solution you picked.
I am in the exact same position as you, looking for an inexpensive, in-line color measurement (expressed as Lovibond) and the signal fed either to the PLC via an analog input channel or fed digitally to the SCADA-interface by an ODBC call (depending how intelligent the instrument is).
Pls. let me hear about your experiences...