Martel Electronics DPM970 User Manual
Dpm 970, Dimensions, Digital ac voltmeter module
DIMENSIONS
All dimensions in mm (inches)
REAR
VIEW
ACV ACI COM COM V+
V-
LP-
LP+
V+
DP1
DP2
DP3
TST
HLD
ALM
XDP
RB
Required F.S.R.
RA2
RB
RA1
200mV
0R
0R
Open
2V
910k
100k
20V
1M
10k
200V
1M
1k
2kV (factory default)
464K
536K
100R
2mA (factory default)
-
-
100R
20mA
-
-
10R
200mA
-
-
1R
2A
-
-
0.1R
20A
-
-
0.01R
➀
➀
➀
➀
➀ ➁
➂
➂
➂
➂
➂ ➃
0R
0R
0R
DPM 970
Digital AC Voltmeter Module
19mm (0.75“) Digit Height
Screw Terminal Connections
Digital Hold
500V a.c. (2kV ) Full Scale Reading
Measures Voltage and Current
LED Backlighting
➁
A 3 ½ digit LCD panel meter, featuring 19mm (0.75“) digit height and LED backlighting, the DPM 970 is a true RMS voltage and current meter with 500V a.c.
(2kV ) and 2mA full scale readings as standard. By changing the value of scaling resistors or adding a shunt, this module will measure most a.c. voltages and
currents. The DPM 970 features auto-zero and suppression of d.c. offset voltage. The digital hold function freezes the last displayed reading. Calibration is
achieved via two multi-turn potentiometers for offset and scale. Connection to the meter is via screw terminals. The module is housed in a robust carrier
which can be bolted in place or panel mounted using the bezel, window and clips provided.
➁
* To ensure maximum accuracy, re-calibrate periodically.
** Maximum safe input voltage across the ACV and COM terminals is 500V
.
RMS
RMS
If voltages to be measured exceed 500V
, then fit scaling resistors
externally to the module.
Specification
Min.
Typ.
Max.
Unit
Accuracy (overall error) *
0.5
1.5
% (±2 count)
Sample rate
3
samples/sec
Operating temperature range
0
50
°C
Temperature s
200
ppm/°C
Frequency range (input voltage)
15
15k
Hz
Input impedance (2kV range)
1
M
DC Supply voltage
7.5
9
14
V d.c.
Supply current (Backlighting off)
1.5
mA d.c.
Supply current (Backlighting on)
50
mA d.c.
Full scale reading **
0
1999
V
Resolution
1
V
RMS
RMS
tability
Ω
@ 5Vd.c.
Stock Number
Standard Meter
DPM 970
61.5 (2.42)
51.0 (2.01)
Ш5.7
(0.22)
24.5
(0.96)
24.0
(0.94)
39.0
(1.54)
Ш3.0
(0.12)
71.5 (2.81)
d
76.0 (2.99)
72.5 (2.85)
40.5
(1.59)
44.0
(1.73)
24.0
(0.94)
51.0 (2.01)
a
b c
a.
1.0 (0.04)
b.
2.0 (0.08)
c.
6.5 (0.26)
d. 11.5 (0.45)
51 (2.01)
24
(0.94)
Display in Test Mode
WEBSITE: http://www.lascarelectronics.com/
Panel cut-out 72 x 40 (2.83 x 1.57)
Maximum panel thickness 3mm (0.12).
SCALING
The value of the three scaling resistors RA1, RA2 and RB may be
altered in order to change the full scale reading (F.S.R.) of the meter
- see table.
The meter will need re-calibration by adjusting the
CAL potentiometer.
To ensure that the meter reads "000" with zero input
voltage/current, short circuit ACV and COM and adjust the ZERO
potentiometer.
NOTE
➀
➂
➃
Use inputs ACV and COM for measuring voltage.
For measuring voltages above 500V RMS, external scaling
resistors must be used.
Use inputs ACI and COM for measuring current.
We recommend the use of a current transformer when
measuring in excess of 10 Amps. Consult current transformer
manufacturer’s data for connections and recommendations.
Other scaling factors can be achieved via the correct selection of
RA1, RA2 and RB values.
➁
CAL ZERO
RA1
RA2