Omega Products DP302 User Manual

3½ DIGIT OHMMETER

DP302-O

U 1999 Count Display Span
U 19.99 Ω to 19.99 kΩ Ranges
U 2-, 3- or 4-Wire Connection
U 120 dB CMR, 70 dB NMR
U 1 mV/deg Count Output
U Bright, 14 mm (0.56") LED Display
U Display Hold and Test
U 115/230 Vac Power
U EMI/RFI Filter for AC Power
U Screw-Terminal Barrier Strip
U Short 104 mm (4.1") Deep

¹⁄₈ DIN Case

Options

U Isolated 9 to 32 Vdc or 26 to

56 Vdc Power

U NEMA 4 (IP65) Splash-Proof

Lens Cover

INSTRUMENTATION

DP302-OR3 shown larger

than actual size.

D

The DP302-O is a low-cost 3½ digit (1999-count)
resistance meter with readout directly in ohms. Four
ranges are jumper-selectable: 19.99 Ω, 199.9 Ω,

1.999 kΩ, 19.99 kΩ. It is complete with low-level
current excitation and open-resistance indication.
The current source is tied to the reference of the A/D
converter for true ratiometric operation and immunity
to changes in line voltage.

STANDARD FEATURES

Electrical features include linearized analog output of
1 mV per count, which is ideal for driving a strip-chart
recorder. Mechanical features include a bright
14 mm (0.56") LED display, a screw-terminal barrier
strip for signal and power, and a compact ¹⁄₈ DIN
case that requires a depth of less than 104 mm (4.1")
behind the bezel.

OPTIONS

Options are isolated 9 to 32 Vdc or 26 to 56 Vdc
power, a PCB edge connector for display control and
output of +4.7 Vdc and - 4.7 Vdc, and a splash-proof
lens cover which meets NEMA 4 (IP65) requirements.

D-1

SPECIFICATIONS

Noise Rejection

NMR: 70 dB, 50/60 Hz
CMR, ANA GND to PWR GND:

120 dB to 60 Hz
CMV, ANA GND to PWR GND: 1500 Vp

per HV test, 354 Vp per IEC spacing

Power

AC Voltages: 115 or 230 Vac, ±15%
AC Frequency: 49 to 440 Hz
DC Voltages: 9 to 32 Vdc, isolated to

300 Vp; 26 to 56 Vdc, isolated to 300 Vp

Power Consumption: 3.7 W
Output Voltages: 4.7 Vdc

and -4.7 Vdc ±5%,10 mA max

Input

Connection: 2-, 3- or 4-wire
Excitation Current: 4 mA or 40 µA
Resistance Break Indication: Meter

displays overrange

Overvoltage Protection: 25 Vp

RANGE RESOLUTION EXCITATION CURRENT ZERO ADJUST

19.99 Ω 10 MΩ 4 mA ±2.5 Ω

199.9 Ω 100 MΩ 4 mA ±2.5 Ω

1.999 kΩ 1 Ω 40 µA ±250 Ω

19.99 kΩ 10 Ω 40 µA ±250 Ω

Display

Type: 7-segment, red LED
Height: 14 mm (0.56")
Symbols: 1.8.8.8
Decimal Points: Three positions

programmable by jumpers or at
connector

Overrange or Break Indication: Three
least-significant digits blank

Accuracy At 25°C

Span Tempco: ±0.01% of reading/°C
Zero Tempco: ±1 m/°C (19.99 Ω and

199.9 Ω ranges), ±0.1 Ω/°C (1.999 kΩ
and 19.99 kΩ ranges)

Full-Scale Step Response: 1 s
Warmup to Rated Accuracy: 10 min

Environmental

Operating Temperature: 0 to 60°C
Storage Temperature: -40 to 85°C
Relative Humidity: 95% at 40°C

(non-condensing)

Analog-to-Digital Conversion

Technique: Dual-slope, average value
Signal Integration Period: 100 ms
Read Rate: 2.5/s

Analog Output (Linearized)

Voltage: 1 mV/count
Calibration Error: Same as given

under accuracy

Current: 1 mA maximum
Source Resistance: 68 Ω

Digital Inputs

Level: TTL or 5V CMOS compatible

Mechanical

Bezel: 96 W x 48 H x 5.1 mm D

(3.78 x 1.89 x 0.20")

Depth Behind Bezel: 104 mm (4.09")
Panel Cutout: 92 W x 45 mm H

(3.62 x 1.77")

Weight: 15 oz (425 g)
Case Material: 94 V-0 UL-rated

polycarbonate

To Order Visit omega.com/dp302-or for Pricing and Details

MODEL NO.

DP302

NOTE: All combinations may not be valid, check online for valid part numbers.
Ordering Examples: DP302-OR1, 3½ digit ohmmeter, 115 Vac power, resistance 0 to 19.99 Ω.

RANGE

-OR1

-OR2

-OR3

-OR4

POWER COLOR DESCRIPTION

3½ digit ohmmeter

0 to 19.99 Ω

0 to 199.9 Ω

0 to 1.999 kΩ

0 to 19.99 kΩ

*

-C1

-C3C

-C3E

-G

(Nothing, leave field blank) 115 Vac, 50/60 Hz power

230 Vac, 50/60 Hz

Isolated 9 to 32 Vdc

Isolated 26 to 56 Vdc

*

(Nothing, leave field blank) red LED display

Green LED display

D-2