The CST305X-DPT differential pressure transmitter (smart DP transmitter, 4–20 mA HART) continuously measures differential pressure, flow and liquid level in industrial processes. It combines a proven capacitive silicon sensor with a microprocessor and high-performance ASIC for long-term stability, high accuracy and easy field configuration. Ranges from 0–1.5 kPa to 0–20,680 kPa, static pressure up to 32 MPa, 4–20 mA + HART output, with Ex ia / Ex d versions for hazardous areas.
The CST305X-DPT is an economical alternative to popular DP transmitters used in power plants, boilers, chemical, water treatment, food and oil & gas industries. Equipment Industrial Solution Co., Ltd (ISE) supplies all ranges and accessories (3-valve and 5-valve manifolds, flange adapters) and configures ranges and square-root output for flow measurement.
Advantages of the CST305X-DPT DP transmitter
- Capacitive or piezoresistive silicon sensor with fully sealed isolating diaphragm assembly.
- 18-bit A/D conversion – high resolution and stable signal.
- Integrated ASIC for signal conditioning, linearisation and current output – vibration-resistant and interchangeable.
- Local zero and span push-buttons, no external pressure standard required.
- Optional LCD with 3-button menu: units, range, damping, output type…
- Electronics housing rotates ±90° for convenient cable entry and display reading.
- Stainless-steel process flanges and robust metal housing for long service life.
- Intrinsically safe Ex ia and flameproof Ex d versions.
CST305X-DPT specifications
| Parameter | Value |
|---|---|
| Range | 0–1.5 kPa to 0–20,680 kPa (multiple range codes) |
| Output | 4–20 mA + HART®; linear or square-root (flow) |
| Power supply | 2-wire, loop powered |
| Diaphragm | 316L stainless steel or Hastelloy C |
| Fill fluid | Silicone oil or fluorinated oil |
| Process connection | ¼” NPT female (3-valve / 5-valve manifold, flange adapters optional) |
| Max. static pressure | 14 MPa / 25 MPa / 32 MPa depending on configuration |
| O-rings | NBR, Viton® (FKM) or low-temperature Viton® (FKM-GFLT) |
| Cable entry | M20 × 1.5 |
| Display | Optional LCD: measured value, % output, loop current, sensor temperature |
| Mounting | 2″ (DN50) pipe or wall/panel bracket (carbon steel or stainless) |
| Explosion protection | Ex ia IIC T4–T6; Ex d IIC T4–T6 (ATEX 2014/34/EU, IEC/EN 60079) |
Accuracy class, ingress protection and approvals depend on configuration and are confirmed on the nameplate and certificates supplied with each unit.
Applications of differential pressure transmitters
- DP flow measurement of liquids, gases and steam with orifice plates, venturi tubes and annubars – square-root output.
- DP level in open and closed tanks (dry leg, wet leg) and boiler drum level.
- Pressure drop across filters, pumps and heat exchangers.
- Process control in power, chemical, oil & gas, water treatment and food & beverage plants.
See more: 10 differential pressure transmitter applications to EU standards.
FAQ
How does a DP transmitter measure boiler drum level?
It measures the difference between the condensate reference column in a balance container and the water column in the drum. ISE supplies the complete CST-DPLM boiler drum level system based on the CST305X-DPT.
When is square-root output used?
For flow measurement with orifice plates or venturis, flow is proportional to the square root of DP. Enabling square-root output makes the 4–20 mA signal directly proportional to flow.
Can it measure very low air DP (cleanrooms, ducts)?
The smallest CST305X-DPT range is 0–1.5 kPa. For air differences of a few tens of Pa, use the CST-MDP low differential pressure transmitter.
Is a gauge pressure version available?
Yes, the CST305X-GPT gauge pressure transmitter shares the same platform – contact us for a quotation.
Related products
- FZ30 3-valve manifold
- Boiler drum level measurement system
- CST-PT pressure transmitter
- CST-VXW vortex flow meter
Where to buy the CST305X-DPT differential pressure transmitter?
EQUIPMENT INDUSTRIAL SOLUTION CO., LTD (ISE) – Ho Chi Minh City, Vietnam – supplies genuine the CST305X-DPT differential pressure transmitter with technical consulting, fast quotation and on-site commissioning support across Vietnam and Southeast Asia.
Contact us: Sales +84 909 617 185 – Technical +84 979 117 185 – Email: [email protected]
