[Boatanchors] W2 Portable Insulation & Capacitance Meter

[William L Howard]

I just picked up a WW II Japanese W2 Portable Insulation & Capacitance
Meter and a translation of the instructions is below.
My questions are: What would "Connect also B1,B2,R1,R2, G, T1, T 2 and
G" likely be connected to?  This unit has also been called a Wheatstone
bridge so I assume the galvanometer must be some form of voltmeter
rather than an ammeter. Yes? No?

Any thoughts, suggestions, etc would be appreciated. Anybody have a WW
II galvanometer they do not want?

Bill

W2 Portable Insulation & Capacitance Meter

How to use:
Fig 1: Connection diagram of insulation resistance meter

Measurement of Insulation Resistance

 First set PD dial to 1/10 and US dial to 1000. Connect L1 and L2 to the
core and
covering (conductor and sheath?) of the cable and connect 100 VDC
between the “+”  & “-”
terminals as in fig. 1. Connect also B1,B2,R1,R2, G, T1, T 2 and G (As
in Fig 1). Open S 2.
Press key K 1, and zero the galvanometer. Open K 1 and close S 2 to the
100,000 W side. Press
K 1 and read the deflection on the galvanometer. Let this deflection be
D. Then the insulation
constant G 1 is given by:

 G1 = D x setting of U.S.   x 0.1
     setting of P.D.
 Next, turn P.D. dial to 1 and close S2 to the line side. Press K 1 and
reduce the dial
setting while noting the galvanometer deflection. When a suitable
deflection is reached, let this
be “A”. Next, using the same method, obtain the deflection for the lead
wire to the cable, which
will be called µ   . The actual deflection due to the cable alone is
then (A - µ  ).  Divide this by
the P.D. setting and multiply it by the U.S. dial setting. Let the
result be “d”. Thus the insulation
resistance of the cable is

 I.R. = G  Megohms
          d

  Measurement of Capacitance
Fig. 2 Capacitance Measurement connection

 Make the connections as shown in Fig. 2. Leave K1 depressed; set P.D.
dial to 1/10 and
close S 3 to the 0.1 MFD side to charge. Next open K 2 and let discharge
through the
galvanometer. Note the deflection on the galvanometer. If the deflection
is too small, reduce the
setting of the P.D. dial to achieve a suitable deflection Let this
deflection be D.  Then:

Capacitance Constant G Ú =  10  x  D
          P.D. Setting

Next close S 3 to the line side. Use the same method described above to
achieve a
galvanometer deflection for K 1 and K 2 which will be called “A”.  Do
the same for the lead wire
and call its deflection µ. The actual deflection for the cable then is
( A - µ). Divide this by the
reading of the P.D. dial and call the quotient “d”.  Then:

Capacitance of the cable  =   d       MFD
          G Ú

Note: Use the same U.S. dial setting for measurement of the standard 0.1
MFD and the cable
capacitance measurement.