ZM-11/U
Capactance-Inductance-Resistance Bridge

© Brooke Clarke, N6GCE 2001 - 2009


ZM11 Front Power On Out of Enclosure

Instruction Manual

NAVMC ELECT 2042, NAVSHIPS 91904 A
Table of Contents
Page 1 -
Page 2 & 3 -
Page 4 & 5 -

Schematic Diagram -

Theory of Operation

In the bridge diagrams "G" is the 1,000 Hz tube generator and HT (Head Telephone) is the eye tube.

Resistance Circuit

Capactance Circuit

Inductance Circuit

Operating Instructions ZM-11/U (on inside of lid)

Installation

Ground the ground lead.  Plug cord into 105 - 125 Volt A.C. line.  POWER to ON.

Electrolytic Capacitors

Connect capacitor, observing polarity, to C posts;
FUNCTION to C CHG;
RANGE to 1, 10 or 100;
advance VOLTAGE CONTROL slowly until meter reads working voltage.
Read leakage on 25, 5, or 1 MA scale.
Balance for C and D while charged.

Insulation Resistance

Connect sample to INS. RES. posts;
FUNCTION to CAL;
OSCILLATOR to D.C. VOLTS;
advance VOLTAGE CONTROL until meter reads 500 Volts.
Adjust CALIBRATE INS. TEST until eye pattern just closes.
Turn FUNCTION to 5000 M or 10,000 M and VOLTAGE CONTROL until pattern again just closes.
Read insulation resistance on meter.

Capacitor Quality

Plug in cable P101 clips open;
FUNCTION and RANGE to CAP QUAL;
D dial to 0;
VOLTAGE CONTROL to 0;
OSCILLATOR to SET METER.
Turn VOLTAGE CONTROL until meter is full scale.
Set OSCILLATOR to OPEN,
turn OSCILLATOR ADJUST until meter is full scale.
Clip leads on capacitor.
If meter stays still capacitor is open.

If meter falls, turn OSCILLATOR to SHORT.
If meter returns to full scale capacitor is shorted.
If meter falls it is not shorted.  SEE MANUAL (NAVSHIPS 91704) FOR LIMITATIONS.

Table 1 - For R, L, C and turns ratio measurements

 
Operation
Resistance
Turns Ratio
Inductance
Inductance
Capacitor
non-electrolytic
Turn Function
switch to
R
N1/N2
L(Q)
L(D)
C
Connect to
Post Marked
R
N1
N2
L
L
C
*For balance
   
Q
D
D
if no balance
 
reverse one
winding &
rebalance
Try L (D)
& rebalance
Try L (Q)
& rebalance
 

Manual

ZM-11 & ZM-11A Manual © Brooke Clarke 2002 (does not include the B version)
Scanned, Bookmarks, Color photos posed like in manual with parts locations.
For Sale on CD-ROM.

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