NF FRA5087, Instruction Manual

Page: 83 / 194

4.4 Input setting
FRA5087
4-9
4.4 Input setting
The input setting involves settings of excessive input level (OVER) detection and of input channel
weighting for analysis input channels, CH1 and CH2. The menu [Input] is used for the setting.
[OVER]
[CH1 LEVEL], [CH2 LEVEL]
These are to set the detection levels for excessive (over) input signal levels. The
FRA5087 has the capability of measuring up to 250 Vrms of input signals due to the
auto-range capability of the analysis inputs. However, any levels that exceed the levels
set here are judged to be excessive (over) input signal levels.
Note, however, that the excessive level setting is nothing to do with the weighting factor
setting in [WEIGHTING FACTOR] below.
[ACTION]
[BUZZER], [SWEEP STOP], [OSC OFF]
These are to be used to set actions when excessive (over) levels were detected.
Each of the above indicates “to activate buzzer”, “to stop frequency sweep” or “to turn
off only AC component of oscillator as well as to stop frequency sweep (DC bias output
is alive)”, respectively.
[WEIGHTING FACTOR]
[CH1], [CH2], [INVERT]
Weighting is to be applied for CH1 and CH2, respectively, within the range of 0 up to
1.0E+6. Resolution is 5 digits or 0.1E-9. For example, if 0.9 has been set for the
weighting factor and 1 V is input, the input signal level is interpreted as 0.9 V. By setting
Invert On, the phase can be inverted (r180
ﾟ
) for measurement.
Note that the weighting factor that is set here does not affect the excessive detection level
mentioned above.
The over detect level and weighting factor relationship is indicated in Fig. 4-6.
CH1
CH2
M
ea
su
re
m
en
t
pr
oc
es
si
ng
[CH1] [CH2]
+
-
+
-
[CH1 LEVEL]
[CH2 LEVEL]
[OVER]
Level comparison
[BUZZER]
[SWEEP STOP]
[OSC OFF]
[ACTION]
[WEIGHTING FACTOR]
Fig. 4-6 Principle of excessive level detection