True-Rms Measurements; Min Max Measurements; Auto Power Off - Amprobe 34XR-A Mode D'emploi

True-rms Measurements

For ac measurements most DMMs average the ac input signal and display the
result as an estimated rms value. This average-responding method is accurate
for sinusoidal waveforms, but can be very inaccurate for distorted waveforms.
To ensure the most accurate measurements, always use a true-rms DMM
when measuring ac voltage or ac current on circuits for the following kinds of
applications:
• Power Supplies - diodes
• Controllers
• Power Limiting - SCR or Triac
• Starting - motors
• Florescent Lighting - ballasts
• Speed Control - motors
• Pulsed Signals
• Any non-sinusoidal ac waveform

MIN MAX Measurements

The MIN MAX function reads and updates the display to show the maximum
or minimum value measured after you press the MIN MAX button.Pressing
the MIN MAX button for less than 1 second will put the meter into a mode of
displaying the maximum, minimum, or actual readings. Each time the button
is pressed, the meter will cycle to the next display mode as shown in the table
below.Press the MIN MAX button for more than 2 seconds to exit MIN MAX.
Button
< 1 second
< 1 second
< 1 second
> 2 seconds
MIN MAX Measurements
Auto Power Off is a battery saving feature that puts the meter into a sleep
mode if the Function/Range Switch has not changed position in the last 30
minutes. To wake the meter turn it off and then on.
The Auto Power Off feature can be disabled to keep the meter from going
to sleep.This feature is useful when using the MIN MAX mode for extended
periods. To disable the Auto Power Off feature use the following procedure:
Display
MAX
MIN
MIN MAX (blinks)
Exit MIN MAX
Value Displayed
Maximum value after feature activated
Minimum value after feature activated
Normal measurement, actual reading
Normal measurement, actual reading
6