Freezing The Readings; Taking A Relative Measurement - Extech Instruments MS400 User Manual

To measure AC current larger than 400mA:
1. Press the AUTO SET key once and ACA
will be visible at the top of the screen.
2. Press F5 to select 20A, the units for the
main reading window will be A.
3. Press the AUTO SET key once and ACA
will be visible at the top of the screen.
4. Plug the current extended module into the
current measurement jack, and plug the test
leads into the shunt.
5. Connect the red and black test leads in
series to the measurement points and the
AC current value will be displayed on the
screen.
6. Press F4 to return to the 400mA
measurement mode.
Freezing a Displayed Reading
Freeze the displayed readings at any time:
1. Press the RUN /STOP key to freeze the
screen, STOP will be displayed at the top right
of the screen.
2. Press the RUN /STOP key again to resume
measurements.

Taking a Relative Measurement

A reading, relative to a reference value, is displayed in the relative measurement mode. The
following example shows how to take a relative measurement. First, the user must define a
reference value:
1. Press the R key and R will be displayed on the
top of the screen.
2. Press the AUTO SET key untill C appears at
the top of the screen.
3. Plug the capacitance extended module into the
capacitance measurement jack.
4. When the reading stabilizes, press F2 and the
triangle icon will be displayed on the top of the
screen. The saved
displayed below the triangle
5. All subsequent readings will be displayed
relative to the stored reference reading.
Figure 30: AC Current Measurement for 20A
reference value is
29
Figure 31: Freezing the Readings
Figure 32: Relative Measurement.
MS400 Version 2.0 – December 2007