IN ROCK’S OPINION THE ELGIN IS THE BEST FANCY SCREWED ON
KNURLED BEZEL AND CASE BACK. PLUS 1MM LARGER THAN WALTHAM OR BOLUVA
MOVEMENTS WERE HIGHER GRADE ALSO.
US ARMY SPECIFICATION NO. 94-27834-B
Dated FEBRUARY 22, 1943 –
WATCH, NAVIGATION, TYPE A-11 (HACK):
F. METHOD OF INSPECTION AND TESTS: F-5. Individual Tests.- Each
watch shall be subject to the following tests: F-5a. Room Temperature Rate
Test –Horizontal Position. – The watch shall be fully wound and run for one
day to allow it to settle down. The daily rate of the watch then shall be
determined for a period of 3 Consecutive days with the watch in a horizontal
position with the dial up and with a daily winding.
The average of the daily rates during the test period shall not exceed
30 seconds. F-5b. Room Temperature Rate Test – Vertical Position. –
The daily rate of the watch shall be determined for a period of 3 consecutive
days with the watch in a vertical position, with the pendant down and with
daily winding. The average of the daily rates during the test period shall
not exceed 30 seconds. The difference between the average daily rate
obtained in this test, and in the test specified in Paragraph F-5a, shall
not exceed 45 seconds. F-6.
Routine Type Test. – The following tests, in addition to those specified
in Paragraph F-5,shall be applied to not less than 5 watches selected
at random from each hundred or fraction thereof that are contracted
for. F-6a. Plus 35 Degrees Centigrade (Plus 95 Degrees Fahrenheit)
Temperature Rate Test – Pendant Down Position.- The watch shall be
fully wound and then subjected to a temperature of plus 35 degrees
Centigrade (plus 95 degrees Fahrenheit) for a period of 5 hours. During
this period, the daily rate of the watch shall not differ more than 20
seconds from the average daily rate obtained in the test specified in
Paragraph F-5b. (In order to arrive at the correct figure for the rate
allowance for the temperature test,the error noted for the 5-hour period
shall be multiplied by 4.8 in order to determine the rate for 24 hours). F-6b.
Zero Degrees Centigrade (Plus 32 Degrees Fahrenheit)-
Temperature Rate Test – Pendant Down Position. –
The watch shall be tested as described in Paragraph F-6a,
except that the watch shall be at a temperature
of zero degrees Centigrade (plus 32 degrees Fahrenheit). The daily rate of the
watch shall not differ more than 40 seconds from the daily rate obtained in
test specified in Paragraph F-5b. F-6c.
Waterproof Test. – The watch shall be suspended above a beaker of water
placed in a vacuum chamber which shall be evacuated to 5 1/2 inches
of mercury (to simulate a condition of 72 inches of water), then the watch
shall be immersed for a period of 15 seconds. There shall be no evidence of
leakage of water into the watch during the test period. Leakage will appear as
bubbles emanating from the back, crystal, or stem of the watch.