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BASIC DMM OPERATION
2.6.7 TRMS AC Voltage Measurements
The in.Wument can make TFNS AC voltage mez+rements
from 1pV to 3OOV.To m&Wire AC volts, proceed as follows:
Setiling Time-&c
to within 0.1% of change in reading.
This time specification does not include A/D conversion
time.
1. Select the AC volts function by pressing the VOLTS and
AC buttons.
2. Select a range consistent with the expected voltage or
use autorange.
3. Select the front or rear panel input terminals
INPUT switch.
AC Voltage
SOWX
using the
MODEL
NOTE
Caution :
Maximum input = 300V RMS. 425V Peak, 1d V. Hz
Input Impedance = 1MR Shunted by < 1 OOpF
There is a small amount of offset (typicaUy 150
counts at 5*/zd) present when using. the ACV
function. Do n&zero
this level o&Paragraph
2.610 provides an explanation
of AC voltage
offset.
4. Con&a
the signal to be measured to the selected
put terminals as shown in Figure 2-6.
199
Figure 2-6. TRMS AC Voltage Measurement
in-
2.6.8 Current Measurements
(DC or TRMS AC)
5. Take the reading from the display.
Clarifications
of TRMS ACV Specificatioik
Maximum AIlowable Input-The
following graph summa&es
the maximum input based on the lOY*Hz
specification.
Maximum
Input
TRMS
AC Volts
Maximum Input TRMS AC Volts
The Model 199 can make DC or TRMS AC current
measurements from lOOn.4 (at Wtd resolution) to 3A. Use
the following procedure to make current measurements.
1. Select the DC current or AC -nt
‘Kiticfion by prrssing
the AMPS button (also press AC for AC current).
2. Select a range consistent with the expected current or
use autorange.
3. Connect the signal to be measured to the front-panel
input
terminals
as shown
in Figure
2-7.
4. Take the reading from the display.
MODEL
199
Front Panel
Caution ; Maximum Continuous input = 3A
Figure 2-7. Current Measurements
2-12