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Lovibond specification for the nearest matches for all the above-mentioned sets of color standards and has also obtained the nearest equivalents in terms of potassium dichromate solutions [31]. From these nearest equivalents it is possible to express color specifications given by any of these means in terms of any other of them, as shown in Table 18 which gives the chromaticity coordinates, $x,y$ , of each of the eighteen Gardner standards for CIE source C, nearest chromaticity match on the Lovibond 35Y + NR scale, the ASTM scale and the Union color scale, together with the nearest lightness match on the Union scale. The Gardner standards define a locus of chromaticities that agrees closely with that of the ASTM standards with only 6 of the 18 standards departing by more than 0.001 as indicated by the letters "p" and "g".

The British Paint Research Station has recommended [151] combinations of Lovibond glasses for color-grading oils and varnishes. Some of the combinations involve colorless or blue glasses to be combined with the oil to match red and yellow glasses, and a device facilitating the setting up of such combinations is also recommended. The Lovibond glasses are mounted in a slide, and the two photometric fields to be compared are brought into juxtaposition by mirrors.

Table 17. *U.S. standards for rosin. Luminous transmittance,* $\tau _{v}$ , *chromaticity coordinates,* x,y, *for CIE source C, and nearest chromaticity match on the ASTM color scale, the 35-yellow plus N-red Lovibond scale, and the Gardner color scale*
Designation		Luminous transmittance	Chromaticity coordinates		Nearest chromaticity match on:
Letter	Name	$\tau _{v}$	x	y	ASTM color scale	35Y + NR scale N	Gardner color scale
X	Extra water white	0.609	0.4339	0.4663	1.4p	1.2p	9.7p
WW	Water white	.531	.4579	.4732	1.7p	2.2p	10.8p
WG	Window glass	.466	.4785	.4741	1.9p	3.2p	11.4p
N	Nancy	.396	.5001	.4704	2.2p	4.4p	11.9p
M	Mary	.322	.5212	.4619	2.6p	6.0g	12.5p
K	Kate	.245	.5430	.4483	3.0p	7.8g	13.2p
I	Isaac	.178	.5649	.4310	3.5p	10.3k	13.9p
H	Harry	.1114	.5879	.4102	4.0p	13.8g	14.9p
G	George	.0723	.6116	.3874	4.6p	18.7g	15.7p
F	Frank	.0398	.6364	.3632	5.3p	27.0g	16.9p
E	Edward	.0131	.6640	.3358	6.1p	44.0g	18.2p
D	Dolly	.0021	.6943	.3057	7.2p	88.0g

Table 18. *The Gardner color standards. Chromaticity coordinates.* x,y, for CIE source C, nearest chromaticity matches on the ASTM color scale and the 35-yellow plus N-red Lovibond scale, and both nearest lightness matches and nearest chromaticity matches on the Union color scale
Gardner color number	Chromaticity coordinates		Nearest chromaticity match on:			Nearest lightness match on Union color scale from Gardner (30)
Gardner color number	x	y	35Y + NR scale N	ASTM color scale	Union color scale
1	0.313	0.324		0.06g	0.12p	−1
2	.318	.333		.12g	.22p	1+
3	.322	.339		.18g	.33p	1−1½
4	.330	.349		.28g	.51p	1−1½
5	.342	.371		.47g	.86p	1−1½
6	.354	.387		.6 g	1.05p	1½−2
7	.372	.410		.8 g	1.25p	2
8	.394	.440		1.0 g	1.45p	2−2½
9	.419	.462	0.7p	1.2 g	1.6 p	2½
10	.444	.475	1.4p	1.5 g	1.75p	2½−3
11	.467	.482	2.3p	1.75g	1.9 g	3−3½
12	.504	.471	4.6p	2.3 p	2.45g	3½−4
13	.535	.454	7.1g	2.85p	3.0 g	4−4½
14	.567	.427	10.6g	3.55p	3.55g	4½
15	.590	.407	14.2g	4.1 p	3.9 g	−5
16	.619	.380	21 g	4.8 p	4.45g	6
17	.638	.361	28 g	5.35p	4.75g	7−8
18	.659	.340	40 g	6.0 p	5.25g	8+

d. Sugar Products

For regulatory purposes, the classification of sugar products (honey, maple syrup, molasses, sugarcane) is conducted visually by comparison with glass chromaticity standards. The source C chromaticity coordinates, $x,y$ , are listed in table 19

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