3
INTRODUCTION
This instrument is a line powered, bench-type digital multimeter with a 4-1/2 digit LED display. The DMM
can measure AC/DC volts, AC/DC current, and resistance. Among other features:
True RMS Measurements of AC or AC+DC Signals :
True RMS measurement is the only accurate way to directly measure AC or AC+DC signals that are not
noise-free pure sine waves. This instrument measures AC voltage frequencies up to 50 kHz.
Five measurement functions :
AC and DC VOLTS: Standard linear voltage measurements from 10 µV to 1200 VDC and 10 mV to 1000
VAC or AC+DC true rms.
AC and DC CURRENT:
Standard current measurements from 10 nA to 20 ADC and 10 µA to 20 AAC or
AC+DC true rms.
RESISTANCE
: Standard resistance measurements from 10 m
Ω
to 20 M
Ω
.
Each measurement range has:
Autopolarity operation. Overrange indication. Effective protection from
overloads and transients. Dual slope integration measurement technique to insure fast, accurate, noise-
free measurements.
Diode test:
Ranges of the resistance function that will turn on PN junctions allowing testing of diodes and
transistors. These ranges are marked with a diode symbol on the front panel of your DMM. The preferred
2k
Ω
range is marked with the largest diode symbol.
Improved test leads:
Finger guards on the probes and shrouded contacts on the input terminals
decrease the possibility of accidental contact with circuit voltage.
Long-term calibration accuracy:
1-year.
UNPACKING YOUR INSTRUMENT
The shipping box should contain this manual, your multimeter, test leads (one red and one black), two
spare fuses (2A); two spare fuses 0.08A (230 V) and 0.125A (117 V), and 2 power cords (1 - 115V and
1- 230 V ). Check the shipment for damage.
CAUTION:
This meter has dual operating voltages. It can be operated from 117VAC or 230VAC source. The unit is
shipped in the 230VAC configuration with an T 0.08A / 250 V fuse installed. If you plan to use the BDM40
on a 117 V source, unplug the power cord, switch to the T 0.125A / 250V fuse (supplied with instrument),
and set the rear panel switch to 117V.
If the meter maybe damaged if is not setup properly for the source voltage being used.
The label on the top side of your instrument is marked with the line voltage and frequency required for
proper operation. Refer to Maintenance section if a change in the input power configuration is desired.
GETTING ACQUAINTED
Your meter is light-weight with a low profile, and requires little space on the work bench. The black case
is made of rugged, high-impact plastic. The handle can be rotated to eight positions. The right side of
your DMM contains two rows of switches and LED display. The power cord receptacle is located on the
rear panel of your DMM. The meter inputs are the 4 inputs on the front panel and are marked for the
functions.
USING YOUR METER
The following paragraphs describe each of the controls on your DMM and how these controls can be
used for each instrument function. Exercises are included to help you familiarize yourself with your DMM
and to verify that your instrument is functional.
