Analytical Method: Gardner Color Measurement for Prove

Method: Spectrophotometric, analogous ASTM D6166

(Color of Pine Chemicals and Related Products - Instrumental Determination of Gardner Color) and analogous DIN EN ISO 4630-2 (Clear liquids - Estimation of colour by the Gardner colour scale - Part 2: Spectrophotometric method)

Materials and reagents:

Cat.No. 116754 Water for analysis

Cat.No. 173016 Spectroquant® VIS Spectrophotometer Prove 100 or
Cat.No. 173017 Spectroquant® UV/VIS Spectrophotometer Prove 300 or
Cat.No. 173018 Spectroquant® UV/VIS Spectrophotometer Prove 600

Cat.No. 114946 Rectangular cells 10 mm
Ultrasonic bath (optional)
Heating bath (optional)
Filter paper or centrifuge (optional)


Spectrophotometric measurement
Evaluation acc. to ASTM D6166 and DIN EN ISO 4630-2 (see the literature[1, 2]).

Measuring range:

1.0 – 18.0 Gardner Color (method No. 2561)

Sample material:

Clear, yellow/brown liquid samples
Pine chemical products (e.g. tall oil, tall oil fatty acids, rosin, and related products)
Drying oils, varnishes, fatty acids, polymerized fatty acids, resin solutions

Working instructions:

Sample preparation:
If the sample contains air or gas bubbles, these bubbles need to be removed by ultrasonic bath treatment.

If the sample is in solid form, the sample has to be melted and homogenized before filling into the rectangular cell.

Overheating of the sample should be avoided.

If the sample is turbid, the sample needs to be filtered or centrifuged to remove the turbidity.

Zeroing the photometer:
For each measurement series, a zero adjustment is required.

It is recommended to use the same cell for zero adjustment and for sample measurement.

The zeroing procedure for the measurement series is automatically prompted by the instrument.

For zero adjustment fill the 10-mm rectangular cell with water for analysis.

After prompting, place the filled rectangular cell in the cell compartment, the zero adjustment is executed automatically.

Confirm the implementation of zero adjustment with "OK".

The zero value is valid for the entire measurement series.

Select method 2561 "Gardner Color" from method list.

Prior to the measurement of the first sample the system automatically prompts a zero adjustment (procedure see "Zeroing the photometer").

Transfer the sample solution carefully into the clean and dry 10-mm rectangular cell and avoid any air bubbles.

Place the rectangular cell into the cell compartment, the measurement is performed automatically.

Confirm measurement with "OK".

The measurement result is shown in the display.

Press "START" to start the measurement procedure for the next sample. The system does not prompt a repeat of the zero adjustment.


  1. ASTM D6166-12, Standard Test Method for Color of Pine Chemicals and Related Products
  2. DIN EN ISO 4630-2, Clear liquids – Estimation of colour by the Gardner colour scale –
    Part 2: Spectrophotometric method
  3. ASTM D1544-04, Standard Test Method for Color of Transparent Liquids (Gardner Color Scale)