Process Instruments
Field instrumentation for pressure, flow and level measurement across industrial processes.
About Process Instruments
Process instruments measure pressure, flow and level out in the plant and send the value to a PLC, DCS or indicator. We supply Siemens SITRANS field instruments for water and wastewater, process plants and utilities.
For pressure, the SITRANS P320 and P420 transmitters cover gauge, absolute and differential pressure from 10 mbar to 700 bar. They also measure level and flow by differential pressure, with accuracy up to 0.065% (P320) and 0.04% (P420). For flow, SITRANS FM MAG 5000 and 6000 transmitters pair with MAG electromagnetic sensors such as the MAG 5100 W for water and wastewater. For level, the 80 GHz SITRANS LR100-series radars and the SITRANS Probe LU240 ultrasonic transmitter give non-contact measurement on tanks, sumps and open channels.
Most of the range works on 4–20 mA with HART, and fieldbus options are available where the control system needs them. We help select the range, process connection and output, and can wire the loop back to the panel.
Key specifications
| Pressure transmitters | SITRANS P320 / P420 — gauge, absolute, differential; 10 mbar to 700 bar |
|---|---|
| Pressure accuracy | Up to 0.065% (P320) and 0.04% (P420) |
| Pressure communication | 4–20 mA/HART, PROFIBUS PA, FOUNDATION Fieldbus, PROFINET over Ethernet-APL |
| Functional safety | P320 / P420 for SIL 2/3 applications per IEC 61508 |
| Electromagnetic flow | SITRANS FM MAG 5000 (±0.4% ±1 mm/s) and MAG 6000 (±0.2% ±1 mm/s), incl. sensor |
| Flow communication | HART on MAG 5000; MAG 6000 add-on modules for HART, Modbus RTU/RS485, PROFIBUS PA/DP, FF H1, DeviceNet |
| Flow transmitter enclosure | IP67 / NEMA 6 (compact and wall mount) |
| Radar level | SITRANS LR100 series, 80 GHz: up to 10 m (LR100), 20 m (LR110 / LR150), 30 m (LR120) |
| Ultrasonic level | SITRANS Probe LU240: 0.2–12 m, 4–20 mA/HART |
Features & benefits
- Pressure transmitters double as level and DP-flow instruments
- Mag flowmeters have no moving parts in the flow path
- 80 GHz radar gives a narrow beam for small tanks and nozzles
- Ultrasonic level for open channels and environmental sites
- HART for remote configuration and diagnostics
- Fieldbus options for PROFIBUS, FOUNDATION Fieldbus and Modbus networks
Where it’s used
- Water treatment and distribution
- Sewage and effluent treatment plants
- Pump stations and wet wells
- Boilers and steam lines
- Chemical and process plants
- Storage tanks and silos
Standards & compliance
Process Instruments — FAQs
Which output do Siemens transmitters provide?
Most of the range uses 4–20 mA with HART. SITRANS P320/P420 also offer PROFIBUS PA, FOUNDATION Fieldbus and PROFINET over Ethernet-APL. The MAG 6000 flow transmitter takes plug-in modules for Modbus RTU, PROFIBUS and others.
Radar or ultrasonic for level measurement?
Ultrasonic transmitters such as the SITRANS Probe LU240 suit clean liquids, sumps and open channels. 80 GHz radar has a narrower beam and handles condensation and vapour better, so it is the usual choice for process vessels and longer ranges.
Can an electromagnetic flowmeter measure any liquid?
Mag flowmeters work on conductive liquids such as water, wastewater and slurries. They cannot measure non-conductive fluids like oils or hydrocarbons. Tell us the fluid and we will confirm suitability.
What details do you need to quote a pressure transmitter?
Give us the pressure type (gauge, absolute or differential), the operating range, the process temperature, the medium, the process connection and the output protocol. Note any hazardous-area requirement too.
