In appearance these are very similar to the commercial range of
AVOmeters.
The following information has been taken from AP 10955H Vol1 Section2
Nov1943
"Testrneters, types C, D, E, F, and H are self»contained instruments, providing the means ofmeasuring wide ranges of voltage, current, and resistance values, and although light and easily portable they are reliable and robust. The instruments are dust and weatherproof and are suitable for both temperate and tropical climates. They are housed in suitable weatherproof cases and the ranges covered are controlled by switches and/or sockets mounted on the front of the instrument. A scale, protected with glass, and appropriately marked, is mounted on the front of the case, and these, together with the necessary terminals, comprise the complete testrneter control equipment. All screws and detachable parts are secured against looseness due to vibration."
It seems that by the time of this publication the services had accepted
the Automatic Coil Winder Company designs as the standard as pictures
of the instruments accompany the descriptions in the above
specification.
Type C With leads and Case 10S/78 Similar to UNIVERSAL AVOMINOR but DC ONLY
Type D with leads. 10S/10610 essentially the same as AVO MODEL40 (Though also made by other manufacturers)
Type D connecting leads NO.4 10S/10612
Type D ` Battery 5]/2000
Type 15 Fuse Testmeter, type D 10S/10611 (for early models only)
Type E connecting leads No.5 10S/10616 essentially the same as DC AVOMINOR
Type E with leads and Case 10S/10613
Type E Leather carrying case IOS/10614
Type E Battery 5]/1723
Type 16 Fuse testmeter, type E 10S/10615
Type F with leads 10S/1 also 5QP/1 essentially the same as AVO MODEL 7 MK1 and Mk2
Type H With leads and case 10S/46 also AD PATT 13301 essentially the same as UNIVERSAL AVOMINOR
Some of these instruments and their accesoriesof tmay have a stores reference starting with10A/ rather than 10S/
I have seen a UNIVERSAL AVOMINOR in a leather case marked ZD00116 which would indicate that this instrument was supplied to the War Office or MOD.
AP1186E Volume 1 section 9 covers the same instuments but also includes two variants of the model D meter made by SEI (Salford Electrical instruments), one in a wooden case with fuse protection and the other with a Bakelite case with mechanical cutout. These are both described as model D2 though the front panels are labelled model D and have the 0S/10610 reference number
It would seem logical that there should also have been models A,B,F and
G but I have not seen or heard of them.
Interpretation of Air Minisrty stores reference numbers mentioned above
5J Batteries Primary and Secondary
5Q Ammeters, Micro-ammeters, Milli-ammeters, Voltmeters and
Milli-voltmeters
10A Miscellaneous Radio (Wireless) Equipment
10S Radio (Wireless and Radar) Test Equipment
Model 7 (ZD 00021)
Admiralty
Pattern Model 47
Admiralty
Pattern Model 48A.
Universal Avometer Model 8 (military
version)
AM stores number 10S/16411 (AM pattern AP12945)
Test set No.1 (military version of Model
8/9
Mark
II)
(NATO part number 6625-99-105-7050)
