Hameg HM8115 Handbuch Seite 20

Controls and Displays
Pressing an AMPERE (10) (11) pushbutton switches the
automatic ranging unit off and the AUTO LED is no longer
lit. Thereafter the measurement range can be selected by
one of the AMPERE (10) (11) pushbuttons. The automatic
ranging unit can be activated again by pressing the right
hand AMPERE (11) pushbutton until the AUTO LED is lit.
The AMPERE display (3) indicates either the current
within the active measuring circuit or overflow if a too
low measurement range had been selected manually.
(12) WATT pushbutton and associated LED.
True power measurement is selected and indicated by
the WATT LED after this pushbutton has been pressed.
Under this conditions the FUNCTION display (4) shows
the true power measurement result.
(13) VAR pushbutton and associated LED.
Pressing this pushbutton switches over to reactive power
measurement. Then the Var LED is lit and the FUNC-
TION display (4) indicates the reactive power and the
load type.
Reactive power caused by inductive loads is indicated
without sign (meaning "+"). In the case of a capacitive
load, the reactive power is displayed in combination with
a negative sign ("-").
Current and voltage must be sinusoidal for correct reac-
tive power measurement. As the apparent power (V x I)
and the true (V x I x cos ϕ) power are independent from
the wave form, the reactive power can be calculated
from these values in case of non sinusoidal wave form.
Note: In some conditions the display may cause the
wrong impression of a faulty instrument. e.g. if reactive
power is indicated although no load is applied. Please
note the instrument specification!
(14) COS ϕ ϕ ϕ ϕ ϕ pushbutton and associated LED.
After pressing this pushbutton the cos
the FUNCTION display (4) shows the cos
result.
20
((15) INPUT 1 / OUTPUT 1
cos ϕ ϕ ϕ ϕ ϕ LED is lit and
cos cos cos
cos ϕ ϕ ϕ ϕ ϕ measuring
cos cos cos
cos ϕ ϕ ϕ ϕ ϕ value can be displayed by the FUNCTION dis-
A cos cos cos cos
play (4) if AC parameters are present with sufficient
amplitude for both voltage and current (see specifica-
tions). In case of insufficient amplitude and DC content,
dashes in changing position are displayed.
Sinusoidal current and voltage is required for correct
cos ϕ measurement. As the apparent power (V x I) and
the true power (V x I x cos ϕ) are independent from the
wave form, cos ϕ can be calculated from these values in
case of non sinusoidal wave form.
Note: In special conditions the display may cause the
wrong impression of a faulty instrument. e.g. if a value
deviating from "1" is indicated although no capacitive
or inductive load is applied. Please note the instrument
specification!
(banana jacks) measuring circuit 1.
INPUT 1 and OUTPUT 1 are the terminals of measuring
circuit 1 and not connected to earth (PE) by the POWER
METER. On condition that the selector switch (6) is set
to "INPUT 1 / OUTPUT 1", the four (safety) banana jacks
(15) can be used for measurement. Both jacks on the
left are marked INPUT 1 for connection with the power
supply. The load must be connected to the jacks on the
right marked OUTPUT 1.
Warning!
The banana plugs may get hot during operation
after passing high currents.
The red banana jacks located in the upper position are
connected galvanically (0 Ohm). Therefore no voltage
must be applied between both jacks (short circuit)!
The precision resistor is located inside the instrument
between the banana jacks in lower position (blue, black).
Again no voltage must be applied between these jacks!
Measuring circuit 1 is protected by a fuse located in the
accessible fuse holder (5). The maximum permissible
current is 16 Ampere (fuse characteristic: very quick act-
Änderungen vorbehalten / Subject to change without notice