[Test-Equipment] HP serial numbers?

[Lars E Pettersson]

On http://www.hpmuseum.org/collect.htm#numbers I found an explanation on 
serial numbers for HP calculators. They stated:

YYWWC#####

YY = number of years since 1960
WW = week number that year
C = country code
##### = serial number that year and week

After 1996 they use

CCYWW#####

CC = country code
Y = last digit of year
the other as before

Is this the way they also numbered test equipment. I checked my HP5328 and 
HP8640 and they fitted nicely into the first version, manufactured 1978, 
and 1979 respectively.

How precise are the dates?

/Lars

-- 
Lars E Pettersson, SM6RPZ
Gothenburg, SWEDEN
sm6rpz@home.se