Operating
Procedure
Making Measur ements wi th the Model s HHM73 and HHM76
wit h an Osci l loscope
·
Connect the current probe to the proper input channel on the
oscilloscope.
·
Begin with the least sensitive range on the current probe (1 mV/A).
·
Select the 0.5 V/Division on your oscilloscope.
·
Turn oscilloscope power on. Turn on (7) the probe: the green LED (6)
should be on, and the red LED (5) off. If the green indicator does not
come on or goes off before the probe has operated for 10 min., it is
necessary to replace the battery (See ÒBattery ReplacementÓ, pg. 18).
·
After approximately 10 minutes of operation, if none of the control
buttons has been manipulated power will automatically shut off (see
ÒAuto-OffÓ, pg. 13).
DC Measurement
·
Select DC position on the oscilloscope.
·
ÒZeroÓ the probe. With the probe disconnected from test samples (no
conductor in probe jaw window), press the auto zero button (4). The
red LED (%) comes on for approximately three seconds to indicate
that the probe is zeroing. If the red LED remains lit, this indicates that
zero has not been attained - repeat the zeroing operation.
Alternatively, you may ÒzeroÓ with the oscilloscope.
·
For best accuracy, especially on low-level measurement, it is
recommended that you zero the probe before each measurement.
·
Clamp the probe around the conductor (1) to be tested. The
oscilloscope should now display the measured conductor current. A
positive reading indicates current flowing in the direction of the arrow
located on the side of the jaw (2). A negative reading indicates current
flow in the opposite direction of the arrow. Multiply the conversion ratio
(1mV/A or 10 mV/A) times the V/Division range on your oscilloscope to
get the value of the current.
AC Measurement
·
Select the AC position range on the oscilloscope.
·
The DC zero adjustment is not required when measuring AC current.
·
Clamp the probe around the conductor (1) to be tested. The
oscilloscope should now display the measured conductor current.
Apply the conversion ratio (1mV/A or 10 mV/A) times the V/Division
range on your oscilloscope to get the value of the peak current.
HHM73
®
600V CAT III - 600A
!
DC
ZERO
OL
ON
600A
OFF
60A
OUTPUT:
600 A: 1 mV/A
60 A: 10 mV/A
HHM73
AC/DC CURRENT PROBE
2
4
7
6
8
1
3
5
9
Ø =1.18" (30 mm)
Cable max.
Ø =0.95" (24 mm)
Dual Cable max.
7. Three-position range
selection switch:
·
On/Off
·
600 A (1 mV/A)
·
60 A (10 mV/A)
8. Coaxial cable, 6.5 ft (2 m)
9. BNC Connector
1. Conductor
2. Jaws
3. Protective non-slip guard
4. Automatic zero DC button
5. Red light (overrange and
incorrect zero adjustment)
6. Green light (on when
battery voltage
³
6.5 V)
12
9
