Measure pressure drop across filters and other process components with the Wahl DP Series differential pressure transmitter. Two pressure ports connect to separate measurement points, allowing a compatible controller, indicator or recording system to follow the difference between them.
The DP Series combines piezoresistive silicon sensing technology with compact 304 stainless steel construction. Select the measuring range, accuracy, output and connections to suit the process medium and receiving equipment.
Differential pressure measurement applications
| Application | Selection considerations |
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| Filter pressure-drop monitoring |
Provide the expected pressure difference across a clean filter and the maximum differential pressure to be monitored, together with the normal line pressure. |
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| Process equipment monitoring |
Specify the two measurement points, process medium and operating conditions so the transmitter range and wetted-material compatibility can be checked. |
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| Hydraulic and pneumatic systems |
Include the working pressure at each port, temperature and any pressure surges or rapid changes. |
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| Machine building and automation |
Match the transmitter output, supply voltage and electrical connection to the machine controller or data acquisition system. |
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| Existing transmitter replacement |
Provide the complete model code, nameplate photograph, wiring details and process connection sizes. |
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Selection point: Differential pressure and line pressure are separate requirements. A small pressure difference can exist between two highly pressurised points. Confirm the allowable pressure at both ports, including one-sided pressure during start-up or isolation, before selecting the transmitter.
Wahl DP Series pressure range options
The catalogue ordering guide lists the following pressure range selections. These are individual ordering options, not a single transmitter with a user-adjustable 5–500 psi range.
| Range code | Catalogue pressure range |
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| 5# |
5 psi |
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| 15# |
15 psi |
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| 30# |
30 psi |
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| 50# |
50 psi |
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| 100# |
100 psi |
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| 300# |
300 psi |
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| 500# |
500 psi |
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| Custom |
Specify the required measurement span and pressure units for review. |
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Include the smallest pressure difference that needs to be measured accurately. If the pressure difference can reverse, state the required positive and negative limits rather than assuming a standard range covers both directions.
Accuracy and operating specifications
| Specification | Catalogue details |
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| Sensor technology |
Piezoresistive silicon. |
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| Construction |
304 stainless steel housing and sensor construction. |
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| Ultra-high accuracy — code U |
0.05% of full scale. |
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| Standard accuracy — code S |
0.08% of full scale, as listed in the accuracy specification table. |
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| Economy accuracy — code E |
0.10% of full scale at the catalogue reference temperature of 23°C. |
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| Accuracy definition |
Includes non-linearity, hysteresis and non-repeatability. |
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| Long-term stability |
±0.10% of full scale per year. |
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| Thermal compensation range |
-20 to +90°C. Thermal performance depends on the selected accuracy option. |
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| Operating temperature |
-40 to +125°C. |
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| Response time |
Less than 1 ms, as listed in the catalogue. |
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Accuracy selection: Full-scale accuracy relates to the selected measurement span, not the instantaneous reading. The operating temperature range is also wider than the thermal compensation range. Confirm the required accuracy over the actual working temperature when ordering.
Output signals and power supply
Choose the signal that matches the receiving instrument. The transmitter supplies a measurement signal; display, recording and alarm functions depend on the connected equipment.
| Output option | Wiring | Catalogue power supply |
|---|
| 4–20 mA |
2-wire |
8–30 V DC |
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| 0–5 V |
3-wire |
8–30 V DC |
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| 0–10 V |
3-wire |
8–30 V DC |
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| 0.5–4.5 V |
3-wire |
12–30 V DC, as listed in the catalogue |
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| 1–5 V |
3-wire |
8–30 V DC |
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Output types are selected when ordering. Confirm the supply voltage, input compatibility, wiring and pressure scaling before connecting the transmitter to a PLC, panel meter or recorder.
Process connections and environmental protection
Catalogue process connection options include male 1/2-inch and 1/4-inch NPT, G1/2 and G1/4 BSPP, R1/2 and R1/4 BSPT, and M20 x 1.5. Specify the exact thread standard and size for the installation.
| Electrical connection | Listed connector protection |
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| EN 175301-803A angular connector |
IP65 |
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| M12 circular connector |
IP67 |
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| Waterproof plug / cable connection |
IP68 |
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The catalogue lists IP67 / NEMA 4X for the enclosure, while connector ratings vary. Confirm the environmental protection of the complete ordered assembly, including the mating connector and cable installation.
Wahl DP Series specification reference
Wahl DP Series differential pressure transmitter specification reference.
Wahl DP Series configuration reference. Confirm the complete model code and ordered specifications before purchase.
Request a selection and quotation
Contact us for pricing and availability. To select a Wahl DP Series differential pressure transmitter, please include:
- Gas or liquid being measured, including composition where relevant.
- Minimum, normal and maximum differential pressure.
- Normal and maximum line pressure at each port.
- Operating temperature and any pressure surges.
- Required accuracy and output signal.
- Process thread type, electrical connector and cable length.
- Quantity, calibration documentation requirements and existing model details, if applicable.
