NTL Multimeter analogue 12 User manual

Take care that the device does not fall. In the event that this does occur, have the
device examined or repaired by authorized service personnel.
In the event that unforeseen difficulties arise during operation, contact the dealer.
Do not subject the device to dripping or sprayed water.
This device may only be operated by qualified personnel or by persons they
instruct in its use.
- Fruhmann GmbH - 7343 Neutal, Austria
P3212-12
Multimeter analogue 12
The analogue multimeter serves to measure DC and AC voltage as well as DC
and AC amperage. An ideal and versatile measuring device with two double
scales, designed specially for students.
The scales 0…3 / 0…10 have the zero point on the left boundary of the scale.
For measurements involving a possible change of the plus or minus sign in
front of the value read, the device can be switched to the scales -5…0…+5 / -
1,5…0 …+1,5 with the zero point at the midpoint of the scale.
The double scale 3 / 10 is mirrored in order to guarantee accurate readings.
The analogue multimeter is electronically overload-protected in all areas.
Technical Data:
Display: Double scale 0 … 3 / 0 … 10, linear, zero-point left, mirrored
Scale arc length: approx. 86 mm
Double scale -5 … 0 … +5 / -1 … 0 … +1, linear, zero-midpoint
Scale arc length: approx. 41 mm
Zero correction: Adjustment screw for mechanical zero-point correction
Measuring device: Moving-coil system
Accuracy: DC voltage: ± 2 %
AC voltage: ± 3 %
General purpose: horizontally or slightly inclined
Measuring ranges: DC and AC voltages:
1 mV, 100 mV, 300 mV, 1 V, 3 V, 10 V, 30 V
DC and AC amperages:
100 µA, 10 mA, 30 mA, 100 mA, 300 mA, 1 A, 10 A
Internal resistance: 100 kOhm/V
Frequency response: -1,5 db at 20 kHz
Overload protection: electronically, with control-light display
(no glass-pipe micro fuse required)
Power supply: 4 x 1.5 V mignon cells (alkaline recommended)
Case: Plastics, ABS
Dimensions: approx. 200 x 140 x 110 mm
Weight: approx. 633 g

1 Double scale 0 … 3 / 0 … 10, linear, to be used for measurements
with zero at the left side
2 Indicator needle
3 “BAT” scale for checking battery capacity
4 Mirrored scale for exact readings
5 Double scale -5 … 0 … +5 / -1,5 … 0 … +1,5, linear, to be used for
measurements with zero at midpoint
6 Mode switch: AC, DC, zero-midpoint, battery check
7 4 mm safety receptacle “COM” (black) - common ground
8 4 mm safety receptacle “V/A” (red), positive terminal for current and voltage
measurements (all measuring ranges up to 1 A)
9 4 mm safety receptacle “10 A” (red), positive terminal for current
measurements (measuring range 10 A)
10 Step switch for selecting measuring range:
1 mV, 100 mV, 300 mV, 1 V, 3 V, 10 V, 30 V
100 µA, 10 mA, 30 mA, 100 mA, 300 mA, 1 A
11 Adjustment screw for mechanical setting of the zero-point
12 Overload-display
Operation:
1) The analogue multimeter is always ready for operation (as long as the batteries are
properly functioning).
2) The type of power to be measured is set by using the mode switch (6). In addition,
in the case of direct current, this switch is used to select between zero at midpoint or
at the left side. The adjustment screw (11) can be turned appropriately in order to set
the needle to zero if necessary.
3/a) When measuring current, set the step switch for selecting measurement range
(10) to the largest possible measurement range, 1 A, for the applicable current type
(AC/DC). Only for measuring current > 1 A the connecting wire is to be unplugged from
receptacle (8) and plugged into receptacle (9). In this fashion the device is automati-
cally switched to the 10 A measurement range. Under alternating current the indicator
needle always moves to the right, under direct current it moves to the right when the
positive terminal of the power source is connected to receptacle "V/A" (8) or "10 A" (9)
and to the left when the positive terminal is connected to receptacle "COM" (7).
3/b) When measuring voltage, only the receptacles “COM” (7) and “V/A” (8) are used.
The step switch for selecting measurement range (10) is set to the largest measure-
ment range, 30 V. Select the appropriate current type using the mode switch (6).
Switch the step switch (10) to a more sensitive range only after the power supply has
been connected. The indicator needle moves in the same way as when measuring
current.
Note: the current measurement range 100 µA corresponds to a voltage measurement
range of 100 mV.
Overload protection: The measuring element and the internal measuring circuits are
electronically protected against the ocurring overload. Due to safety reasons, a maxi-
mum voltage of 42 V is not to be exceeded.
Battery check: Turn the mode switch (6) all the way to the left. If the needle moves
all the way to the right within the measuring scale "BAT", then the batteries' capacity
is alright. In order to replace the four 1.5 V mignon cells, remove the rear panel. Only
alkaline batteries are recommended to be used with this device.
Turning off the measuring device: If the mode switch (6) is set to DC („OFF“), the
set of batteries should theoretically last about 10 years. The effective operating time
is limited by the natural durability of the batteries (Please check the information on the
battery package).
Should the device not be used for several months at a time, remove the batteries so
as not to damage the device in the case of battery seepage.
A special feature of this device is the very good frequency response: typical -1,5 db at
20 kHz. Therefore measurements are possible in all kinds of resonance circuits.
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