8
2.4 Function Descriptions
In addition to the conventional measurement functions this meter also possesses
some special functions as follows:
• T
Trru
ue
e E
Effffe
ec
cttiiv
ve
e V
Va
allu
ue
e ((T
TR
RU
UE
E R
RM
MS
S)) m
me
ea
as
su
urre
em
me
en
ntt:: All the measurement values of
this meter on the AC voltage and AC current are true effective values, which
distinguishes this meter from less accurate meters which can only measure
the AC average value.
• d
dB
Bm
m m
me
ea
as
su
urre
em
me
en
ntt:: This is a value calculated and displayed under the current
AC voltage, with a virtual resistance ‘R’ obtained through ‘R
RA
AN
NG
GE
E’ key and
according to the following formula: 10/og
10
(1000V
2
/R).
It is the AC power expressed in the logarithmic form.
• D
DC
C+
+A
AC
C m
me
ea
as
su
urre
em
me
en
ntt:: When measuring voltage or current you have the choice
of both AC and DC mode. In case of selecting the DC+AC measurement
mode, this meter will perform measurements on both DC and AC respectively
and then calculate and display the results according to the following formula:
√√
DC
2
+ AC
2
.
DC+AC measurements reflect the general effective values generated jointly by
both the DC and AC components.
• A
Au
utto
om
ma
attiic
c a
an
nd
d M
Ma
an
nu
ua
all rra
an
ng
ge
es
s:: When you turn ‘on’ the meter power is set to the
Automatic range by defaults (AUTO displaying), and simultaneously it will
automatically select the proper range according to the measured electric
parameters. If ‘OL’ is displayed under automatic range, it indicates the
measured value exceeds the meters maximum range. Press the ‘R
RA
AN
NG
GE
E’
key under the automatic range and the meter will change to manual status
(MANUAL displaying), then pressing the ‘R
RA
AN
NG
GE
E’ key again and it will be
possible to select the required range. The indicator for range will display the
maximum value of this range. If ‘OL’ displays under the manual status
this indicates the measured value exceeds the selected range. Press the
‘R
RA
AN
NG
GE
E’ key under the manual range for 2 seconds and then release, the
meter will revert back to the automatic status.
• L
Liin
ne
ea
arr F
Frre
eq
qu
ue
en
nc
cyy M
Me
ea
as
su
urre
em
me
en
ntt:: Pressing the ‘~
~H
Hz
z’ key allows you to perform
measurements on AC voltage or current as well as a mixture of AC and DC
signals to measure the frequency of AC components. However there are
special requirements on the amplitude of the AC component.
• L
Lo
og
giic
c IIm
mp
pu
ulls
se
e D
Du
uttyy R
Ra
attiio
o M
Me
ea
as
su
urre
em
me
en
ntt:: Logic impulse duty ratio refers to (high
level width/impulse cycle) × 100%.
• D
Diio
od
de
e M
Me
ea
as
su
urre
em
me
en
ntt:: During diode measurement the meter indicates forward
voltage drop of the diode.
5163420K_Instructions.qxd 18/09/2009 12:56 Page 8
