M145-0-0-23-0 Simpson, M145-0-0-23-0 Datasheet - Page 2
M145-0-0-23-0
Manufacturer Part Number
M145-0-0-23-0
Description
Digital Panel Meters DCA 20mA 4.5
Manufacturer
Simpson
Type
DC Current Meterr
Specifications of M145-0-0-23-0
Equipment Type
DC Current Meter
Display Type
7 - Segment LCD
Accuracy
±0.04% %
Bezel
0.945 in. x 2.835 in.
Brand/series
M145
Common Mode Rejection Ratio
90 dB (Min.) @ 60 Hz
Connection Type
Wire Leads
Current, Rating
20 mA
Cut Out, Panel
0.874×2.677 "
Depth
0.473 in.
Digit Height
0.5
Dimensions
2.84"L×0.43"W×0.945"H
Display Digit Height
0.5 "
Display Resolution
1 μA
Function
Ammeter
Humidity
0 to 85%
Indicator Type
4-1⁄2 Digit
Material, Casing
ABS
Meter Type
Digital
Number Of Digits
4-1/2
Primary Type
Electronic
Range, Measurement
20 mA
Temperature, Operating
0 to 55 °C
Voltage Drop
200 mV
Voltage, Supply
5 VDC
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
These instruments are designed for maximum safety
to the operator when mounted in a panel according
to instructions. They are not to be used unmounted
or for exploratory measurements in unknown circuits.
A reversed polarity power supply will permanently
damage this instrument.
IN HIGH and IN LOW must remain within the limits of
the power supply breakdown voltage.
No internal isolation provided. Each meter requires
an isolated power supply. Supply voltage must also
be isolated from the circuit being measured.
A positive reading will be displayed when IN Hi is
more positive than IN Low.
Internal Reference: REFOUT must always be con-
nected to REFIN unless an external reference is
being used.
External Reference: Connect between REFIN and
ANALOG GROUND; REFOUT should then be uncon-
nected (open). For best results, external reference
voltage should be in the range of 50mV to 150mV.
System stability is then only as good as the external
reference.
Calibration
Model M145 has two internal adjustments on the
rear panel, one that is covered by a label, and one
that is always exposed. The exposed adjustment is
a “fine” calibration point, and the covered adjustment
is for “coarse” calibration. Apply an appropriate cur-
rent input for a near full scale reading, typically 19000
counts on the display.
function, REFOUT must be connected to REFIN.
Once a unit has been calibrated with the “coarse”
adjustment, future calibrations should be performed
with the "fine" adjustment only.
Backlight Power Supply
A 2-pin connector is included with the unit if back-
lighting is specified. The right pin is the Positive, and
the left pin is for the Negative power supply. See the
Rear Connections diagram for location.
DISPLAY
Type: 7-segment LCD
Height: 0.5” (12.7mm)
Decimal point: 3-position programmable
Overrange indication: Most significant = “1”
Backlighting: Optional negative image, red
backlighting at 5, 10, 12, 24, or 48VDC
Polarity: Auto with “-” indication, “+” indication
implied
POWER REQUIREMENTS
DC Power: ±5V, +5V, and +9V
(Low battery indication provided with 9V units)
Power supply current: 2mA max
Backlight supply current: 50mA typical
For 24 and 48VDC, 10mA typical
ACCURACY @ 25°C:
±(0.04% of reading + 1 count)
Safety Symbols
Specifications
Connections
The WARNING sign denotes a hazard. It
calls attention to a procedure, practice, or
the like, which, if not correctly performed
or adhered to, could result in personal
injury.
The CAUTION sign denotes a hazard. It
calls attention to an operating procedure,
practice, or the like, which, if not correctly
adhered to, could result in damage to or
destruction of part or all of the instrument.
For these adjustments to
Input Signal
Input Signal
Input Signal
ENVIRONMENTAL
Operating Temperature: 0 to 55°C
Storage Temperature: -10 to 60°C
Relative Humidity: 0 to 85% non-condensing
Warmup time: Less than 20 minutes
Temperature Coefficient: (All inputs)
NOISE REJECTION
NMRR: 60dB, 50/60Hz
CMRR: (with 1KV unbalanced @ 60 Hz): 90dBmin
ANALOG TO DIGITAL CONVERSION
Technique: Integrating
Rate: 3 samples/second-typical
MECHANICAL
Bezel: 0.945” x 2.835”
Basic Unit
M145
In Hi
In Low REFOUT Supply
In Hi
In Low REFOUT Supply
In Hi
In Low REFOUT Supply
In Hi
In Low REFOUT Supply
(0.2% of input
Ordering Information
(24mm x 72mm)
Mini Current Indicators can be configured by making an entry for each box
4-1/2 Digit Indicator
Ground
Ground
Ground
Ground
Analog
Analog
Analog
Analog
Positive
Positive
Positive
Positive
Supply
0.2 digit) / C
DP4
DP4
DP4
DP4
0
1
9 VDC Power Supply
+5 VDC Power Supply
±5 VDC Power Supply
Optional Connections
Non Backlight
Negative Image Red
Negative REFIN
Negative REFIN
Negative
Display
Negative
Supply
Supply
Supply
Hold
Hold
Hold
Hold
REFIN
REFIN
DP1
DP1
DP1
DP1
DPM Power Supply
DP2
DP2
DP3
DP2
DP3
DP3
DP3
DP2
0
1
2
Depth: 0.473” (12mm)
Panel cutout: 0.874” x 2.677”
Weight: 10oz (28.3g)
Case Material: 94-VO, UL-rated ABS
INPUTS: DC Current
+5VDC
±5VDC
+9VDC
200mA
Range
200 A
20mA
2mA
VDC
VDC
VDC
VDC
+5
-5
5
9
+
+
-
-
Decimal Point: DP 1 is the first decimal
point to the left of the least significant digit.
Connect DP# to Positive Supply to activate.
Unneeded features should remain uncon-
nected.
Display Hold: The display can be held
indefinitely by connecting Hold to Positive
Supply. The display will function normally
when this connection is removed.
Resolution
100 A
(22.2mm x 68mm)
10 A
10 A
1 A
21
22
23
24
Range
DP4
Rear Connections
200mA
200 A
Decimal Point
20mA
2mA
Mini M145
Voltage
200mV
200mV
200mV
200mV
Drop
DP3
DP2
0
1
2
3
4
5
Input (unfused)
Backlight Power
Maximum
DP1
100mA
400mA
10mA
40mA
10VDC
12VDC
24VDC
48VDC
5VDC
None