NPFC - MIL-M-16034
METERS, ELECTRICAL-INDICATING (SWITCHBOARD AND PORTABLE TYPES)
| Organization: | NPFC |
| Publication Date: | 2 January 1953 |
| Status: | inactive |
| Page Count: | 23 |
scope:
This specification covers switchboard and portable electrical-indicatin
The type designation of meters shall be in the following form, and as specified (see 3.27 and 6.2):
Meters covered by this specification are designated by the two-letter symbol "MR."
The style is designated by a two-digit number which signifies the following characteristics:
The first digit designates the nominal size and shape of flange on switchboard meters, as follows:
4-4½-inch, rectangular flange.
6-6-inch, rectangular flange.
The first digit designates the accuracy classification of portable meters, as follows:
5-0.5 percent for d.c. meters; 0.75 percent for a.c. meters.
7-0.25 percent.
The second digit designates the type of mounting and the nominal scale length in angular degrees, as follows:
8-Flush mounting, 90° nominal scale.
9-Flush mounting, 250° nominal scale.
The second digit designates the number of scale ranges, as follows:
1-Single range.
2-Double range.
3-Triple range.
The color scheme of the dial background, markings, and pointer is designated by a single letter, as follows:
B-Black dial background, white markings and pointer.
W-White dial background, black markings and pointer.
The full-scale value of single-range meters with zero at left is represented by three figures designating the maximum number of units indicated; when the full-scale value is less than three figures, zeros are inserted at the left to fill out to three figures. Where the letter "R" is used in this group, between two figures, it represents a decimal point. Example: 1R5 represents 1.5.
The full-scale value of multiple-range meters with zero at left is represented as described for single-range meters in 1.2.1.4.1, except that the largest full-scale value is selected for the type designation. Other ranges for each multiple-range meter of a given type designation are as specified. (See 3.27.)
The full-scale deflection of zero-center or offset zero meters is indicated by two numbers designating the numerical value of the end-scale points, with a letter between them designating the decimal value of the numbers, as follows:
D-tenths Example: 5D5 represents 0.5-0-0.5.
U-units Example: 1U9 represents 1-0-9.
T-tens Example: 2T2 represents 20-0-20.
H-hundreds Example 5H5 represents 500-0-500.
Two letters designate the kind of current for which the meter is designed, as follows:
AC-Alternating current (60 cycles per second, nominal frequency).
AD-Alternating current (60 cycles per second, nominal frequency), and direct current.
AE-Alternating current (800 cycles per second, nominal frequency).
AF-Alternating current (400 cycles per second, nominal frequency).
AM-Alternating current (50 to 1,000 cycles per second).
AT-Alternating current (25 to 2,400 cycles per second).
DC-Direct current.
RF-Radio frequency, conventional scale.
RL-Radio frequency, linear expanded scale.
Two letters designate the electrical units indicated by the meters, as follows:
UA-Microamperes.
MA-Milliamperes.
AA-Amperes.
KA-Kiloamperes.
MV-Millivolts.
VV-Volts
KV-Kilovolts.
A single letter designates a special feature, as follows:
H-High-impact-shock resistant.
The four letters "SPEC" are used in place of the letters specified in 1.2.1.5 and 1.2.1.6 for meters having special characteristics, such as adjusted resistance, special scale marks, and so forth. These meters are arbitrarily assigned serial numbers which are to be used in place of the three figures called for in 1.2.1.4.
The type designation MR49W300DCVVH signifies:
(a) MR -Electrical-indicati
(b) 49 -4½-inch rectangular flange, switchboard meter, flush-mounting, 250° nominal scale.
(c) W -White dial background with black markings and black pointer.
(d) 300 -Zero left, full-scale value of 300.
(e) DC -Designed to be energized by direct current.
(f) VV -Electrical units in volts.
(g) H -High-impact-shock resistant.
The type designation MR72W020ADAA signifies:
(a) MR-Electrical-indica
(b) 72 -0.25-percent accuracy class portable meter with two ranges.
(c) W -White dial background with black markings and black pointer.
(d) 020-Full-scale value of 20 for highest range.
(e) AD-Designed to be energized by 60-cycle alternating current and direct current.
(f) AA-Electrical units in amperes.
intended Use:
Switchboard meters are intended for use in general application of electrical measurement including shipboard and land installations. High-impact-shock-re
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