1、AMSC N/A FSC 6645 INCH-POUND MS21341H 19 October 2012 SUPERSEDING MS21341G 15 December 1982 DETAIL SPECIFICATION SHEET METER, TIME TOTALIZING, HERMETICALLY SEALED, 28 VDC This specification is approved for use by all Departments and Agencies of the Department of Defense. The requirements for acquiri
2、ng the product described herein shall consist of this specification sheet and MIL-DTL-7793. FIGURE 1. Meter configuration. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 2 NOTES: 1. Dimensions are in inches. 2. Unless otherwise specified, t
3、olerance is .02 for two place decimals and .005 for three place decimals 3. For design feature purposes, this specification sheet takes precedence over documents referenced herein. 4. Referenced documents shall be of the issue in effect on the date of invitation for bid. 5. Optional radius applies t
4、o all corners and edges. 6. Exposed tin plate on this surface of mounting flange only, per ASTM-B545, to provide an electrical ground for the case. 7. Marking surface is optional. Marking must not be obscured by mounting bracket. 8. Polarity marking (+) near positive terminal on this surface. REQUIR
5、EMENTS: 1. Dimensions. See Figure 1 and Table I. 2. Electrical. Unless otherwise specified, all tests shall be at room pressure and temperature, approximately +23 C. 3. Meter range. 0 to 9999 hours. 4. Scale designator. Hours 5. Mounting flange. Per Note 6 above, tin-plate .0002 to .0004-inch thick
6、to provide means for electrical ground of the case (see Figure 1). 6. Transient protection. No temporary or permanent degradation shall be produced in the meter for the input voltage and time values shown on Figure 2 and Figure 3 (80V and 600V transient, respectively). 7. Ripple protection. The mete
7、r must maintain the accuracy specified in Table I when subjected to a cyclic peak of ripple voltage of less than 2.0 VDC and the frequency-voltage coordinates of Figure 4. 8. Operational check. The meter shall register accurate time over the input voltage range specified in Table I between -65 C and
8、 +125 C. 9. Case finish. The case shall be finished in a durable, dull or semi-gloss black color. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 3 FIGURE 2. Transient surge step function loci limits. DC Volts Time (Seconds)Provided by IHSNo
9、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 4 FIGURE 3. Envelope of spike voltages for direct current. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 5 FIGURE 4. Frequency characteristics of rip
10、ple in 28 VDC electric systems. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 6 10. Marking. The meter shall remain clearly and legibly marked with the following information after subjection to the environmental requirements: (a) Part numb
11、er (Example: MS21341A-05) (b) Source and date code per MIL-STD-1285. (c) 28 VDC Nominal Voltage. TABLE I. Meter configuration and requirements. Requirement MS21341A MS21341B Case Length, Inch (See Figure 1) 1.094/1.047 2.062/2.000 Maximum Weight, Ounce 0.6 1.5 Input Voltage Range, VDC 10 to 34 23 to
12、 32 Nominal Input Power, Watt 0.085 (Average) 1.000 Maximum Input Power, Watt 0.150 (Average) 1.500 Accuracy, Percent 0.1 1.0 TABLE II. Mount setback dash numbers and dimensions (see Figure 1). Dash Number Dim A .015 Dash Number Dim A .015 Dash Number Dim A .015 -01 .000 -10 .281 -19 .562 -02 .031 -
13、11 .312 -20 .594 -03 .062 -12 .344 -21 .625 -04 .094 -13 .375 -22 .656 -05 .125 -14 .406 -23 .688 -06 .156 -15 .438 -24 .719 -07 .188 -16 .469 -25 .750 -08 .218 -17 .500 -26 .781 -09 .250 -18 .531 11. Conformance inspection. The following tests, run in the order shown on all meters, supersede the in
14、dividual tests and sampling Plans A and B specified in MIL-DTL-7793. The maximum meter reading at the time of delivery shall be 0001. (a) Examination of product. (b) Operational shock shall consist of ten (10) operations for instant starting at ambient temperature, approximately 25 C, five each at m
15、inimum and maximum input voltages specified in Table I of this specification sheet. (c) Thermal shock per MIL-STD-202, Method 107, test condition B, modified as follows: Test conditions: 1. During step 1, the meter shall be operated at its maximum input voltage as specified in Table I of this specif
16、ication sheet. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 7 2. During step 3, the meter shall be operated at its minimum operating voltage as specified in Table I of this specification sheet. MEASUREMENTS DURING CYCLING 1. The meter sha
17、ll show no evidence of damage and shall not malfunction. (d) Operation at room ambient (25 C 5 C) and 28 VDC for 20 hours 1 hour. (e) Hermetic seal. (f) Insulation resistance. (g) Sea level dielectric stress (600V RMS, 2 to 5 seconds) (h) All meters failing one or more of these conformance tests sha
18、ll be rejected. 12. In addition to the above tests, three sample meters total (any part number) shall be subjected to the following tests every twenty four months. (a) Salt spray. (b) Vibrations. (c) Shock. (d) Life. Meters shall be operated at input voltage limits specified in Table I, for 100 hour
19、s in each of the following sequences: (1) Maximum voltage at 125 C. (2) Minimum voltage at 125 C. (3) Maximum voltage at -65 C. (4) Minimum voltage at -65 C. (5) 28 VDC at room ambient. (e) Voltage rise time as follows: (1) Apply a voltage rising from zero to maximum input voltage in: (a) 3 millisec
20、onds maximum (b) 2 .5 seconds (2) Repeat both (a) and (b) tests five (5) times. (3) The meter shall start in each case. At the conclusion of these tests, meter readings shall be within the accuracy specified in Table I. Qualification test. The qualification tests are to be conducted in accordance wi
21、th MIL-DTL-7793, except that four (4) sample meters (designated 1, 2, 3 and 4) shall be submitted to Group 1 tests per Table III of this specification sheet. Samples designated 1 and 2 shall be submitted to Group 2 test and samples designated 3 and 4 shall be submitted to Group 3 tests. Provided by
22、IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 8 TABLE III. Qualification tests. Test Requirement Paragraph Test Paragraph Group 1 Examination of product 3.8.1 Visual examination (4.4.1) 3.7.2 3.7.3 3.7.6 3.9 Operational check 3.8.2 4.4.2 Group 2 Power
23、 supply tolerance 3.8.4 4.4.4 Insulation resistance 3.8.5 4.4.5 Dielectric strength 3.8.6 4.4.6 Altitude 3.8.7 4.4.7 Thermal shock 3.8.8 4.4.8 Moisture resistance 3.8.9 4.4.9 Salt spray 3.8.10 4.4.10 Vibration 3.8.11 4.4.11 Shock 3.8.12 4.4.12 Hermetic seal 3.8.13 4.4.13.1 Group 3 Life accuracy 3.8.
24、14 4.4.14 Electromagnetic compatibility 3.8.15 4.4.15 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MS21341H 9 6. Changes from previous issue. Marginal notations are not used in this revision to identify changes with respect to the previous issue d
25、ue to the extent of the changes. Referenced documents. In addition to MIL-DTL-7793, this specification sheet references MIL-STD-1285, MIL-STD-202, and ASTM-B545. Custodians: Preparing activity: Navy - AS Navy - AS Air Force - 99 Project 6645-2012-020 Review activity: DLA - GS1 NOTE: The activities l
26、isted above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at https:/assist.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
