MIL-D-537F
3.5.1.2 Type II (chlorine) disks. When tested as specified in 4.5.2.4 or 4.5.2.7, as applicable,
the characteristics of type II disks shall conform to table II and the accuracy of classes 1, 2, 3, 6,
and 7 disks shall conform to table III. Unless otherwise specified (see 6.2), the disks shall be
standardized for use with acid orthotolidine indicator solution using viewing tubes having a
26 mm viewing depth. The class 4 and 5 disks shall match the master color standard disk
(see 3.8). The coloring of the glass color standard shall be such that the same reading will be
obtained when used with diffused daylight, incandescent light, and white fluorescent light.
TABLE I. Characteristics and accuracy of type I disks.
Class
Range
Interval
Tolerance
Indicator solutions
0.2
±0.04
Bromophenol blue conforming to
3.0 to 4.6
1
CAS 62625-28-9
0.2
±0.04
Bromocresol green- bromocresol
4.4 to 6.0
2
purple conforming to MIL-I-536, type I
0.2
±0.04
6.0 to 7.6
Thymol Blue =
3
3,3-Dibromothymolsulfonaphthalein
0.2
±0.04
7.6 to 9.2
Cresol red-thymol blue conforming to
4
MIL-I-536, type II
0.2
±0.04
6.8 to 8.4
5
Phenol red D
0.2
±0.04
8.6 to 10.0
6
Phenolphthalein D, commercial grade
0.5
3.0 to 7.0
±0.04
7
Wide range indicator solution
3.0 to 11.0
1.0
*
8
Wide range indicator solution
* Shall match master color standard disk (see 3.8) or buffered indicator solution specified in
4.5.2.1. If procedures specified in 4.5.2.1 are used, tolerance on each value shall be ±0.1 pH.
6
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business