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Brand: Endress+Hauser (E & H)
Endress+Hauser Promass A 300 Coriolis Mass Flowmeter
Description
Promass A 300 Coriolis flowmeter with high-pressure option and flexible I/O
The Endress+Hauser Promass A 300 is a single-tube Coriolis mass flowmeter for the lowest flow rates in process plants. It shares the DN 1, DN 2 and DN 4 sensor with the Promass A 100, but pairs it with the larger Proline 300 transmitter: a compact dual-compartment housing with a backlit touch display, WLAN access, a web server and up to three freely assignable inputs and outputs. A high-pressure tube option takes the process rating to 430.9 bar (6,250 psi), well above what most small Coriolis meters offer. Seven Star LLC supplies the Promass A 300 in Oman and the GCC as an independent supplier in Muscat.
The meter measures mass flow, density and temperature directly, and reports volume flow, corrected volume flow and reference density. Liquid full-scale values are 20, 100 and 450 kg/h for DN 1, 2 and 4.
Reading the Promass A 300 model name
- Promass A: bent single-tube sensor for minimum flows, self-draining in all sizes.
- 300: the Proline 300 transmitter with a separate connection compartment, available in coated aluminium or hygienic stainless 1.4404 (316L), and with an optional remote display.
- Order option HB for the measuring tube material selects the high-pressure Alloy C22 version, which is always supplied with a rupture disk.
The exact configuration comes from Endress+Hauser order codes. If you are replacing a meter, send the nameplate; if it is a new project, send the duty data and we will build the code with you.
Promass A 300 technical specifications
| Parameter | Specification |
|---|---|
| Manufacturer / part number | Endress+Hauser / Promass A 300 (Proline Coriolis flowmeter) |
| Nominal diameters | DN 1, DN 2, DN 4 (1/24, 1/12, 1/8 in) |
| Liquid full-scale values | 20 / 100 / 450 kg/h (DN 1 / 2 / 4) |
| Mass and volume flow accuracy (liquids) | ±0.10 % of reading |
| Mass flow accuracy (gases) | ±0.35 % of reading |
| Density accuracy (liquids) | ±0.0005 g/cm³ reference; ±0.001 g/cm³ standard; ±0.002 g/cm³ wide-range |
| Repeatability | ±0.05 % (liquids); ±0.15 % (gases); density ±0.00025 g/cm³ |
| Zero point stability, standard | 0.0005 / 0.0025 / 0.0100 kg/h (DN 1 / 2 / 4) |
| Zero point stability, high pressure | 0.0008 / 0.0040 / 0.0160 kg/h (DN 1 / 2 / 4) |
| Medium temperature | −50 to +205 °C |
| Process pressure | Up to 430.9 bar (6,250 psi) with the high-pressure version; clamp connections to 40 bar |
| Wetted materials | Measuring tube 1.4435 (316/316L) or Alloy C22 (2.4602); connections 1.4404, 1.4435 or Alloy C22 |
| Supply voltage | DC 24 V ±20 % or AC 100 to 240 V (−15 / +10 %), 50/60 Hz; maximum 10 W |
| Ambient temperature | −40 to +60 °C (−50 to +60 °C with option JP); display readable −20 to +60 °C |
| Protection | IP66/67, Type 4X; IP69 with sensor option CM |
| Operation | Touch display, web server via WLAN or service port, FieldCare / DeviceCare |
| Weight (DN 1 / 2 / 4) | 5.35 / 6.9 / 8.75 kg with VCO couplings; +2 kg for the Ex d transmitter |
Inputs, outputs and fieldbus options on the Promass A 300
The transmitter offers a primary 4-20 mA HART output with active or passive mode, plus up to two further I/O channels chosen from current output, user-configurable I/O, pulse/frequency/switch, double pulse, relay, current input and status input. Digital variants include Modbus RS485, EtherNet/IP, PROFIBUS, PROFINET, and Ethernet-APL for PROFINET and Modbus TCP. The Gas Fraction Handler function, available on the HART, Modbus RS485 and PROFINET versions, stabilises readings when a second phase such as gas bubbles disturbs a liquid line.
Promass A 300 design and measuring principle
A single bent tube is excited at resonance while a counter-mass cancels reaction forces. Flow induces a phase shift between inlet and outlet pickups proportional to mass flow; density follows the resonance frequency; tube temperature is used for compensation. The sensor is made from 1.4404 stainless steel, and a rupture disk with a trigger pressure of 10 to 15 bar can be fitted, with an optional drain connection to guide any escaping fluid to a safe discharge.
Safety and approvals for the Promass A 300
Hazardous-area versions are covered by separate Endress+Hauser safety instructions. With the Ex approval options the datasheet states equipment protection level Gb (Zone 1 in the measuring tube) for DN 1 and Ga/Gb (Zone 0 in the tube) for DN 2 and DN 4. The device can be used in flow monitoring up to SIL 2 on a single channel and SIL 3 with homogeneous redundancy when ordered with the functional-safety option, evaluated to IEC 61508. Material certificates to EN 10204 3.1, pressure test reports and radiographic testing of welds (including NORSOK M-601) are orderable extras. Only the options you order carry these documents.
Where the Promass A 300 fits compared with related models
Choose the Promass A 100 when you need a lean HART or fieldbus meter with an ultra-compact transmitter. Choose the Promass A 300 when you need more I/O, a larger display, SIL options or the high-pressure tube. For larger lines the Promass E 300 and Promass H 300 use the same transmitter on bigger sensors.
Selection checklist for the Promass A 300
- Fluid or gas, density, and whether two-phase flow is possible.
- Flow range per size, and gas range calculation if applicable.
- Pressure rating: standard or the high-pressure tube option HB.
- Connection: flanges, Tri-Clamp, 4-VCO-4, or BSPP / NPT internal thread.
- Transmitter housing, power supply and I/O or fieldbus layout.
- Zone marking, SIL requirement and test certificates.
Installation, commissioning and maintenance of the Promass A 300
Choose a mounting point that avoids gas collecting in the tube, such as the lowest point of a vertical line or downstream of a pump, and do not insulate the transmitter housing when the line is lagged. Zero adjustment is done at standstill with the tube full. The unit stores configuration in a plug-in memory, so an electronics module can be swapped without losing settings. WLAN is enabled according to your site cyber-security policy and should be switched off or protected with a new passphrase on sensitive sites.
Typical applications of the Promass A 300 in Oman and the GCC
High-pressure low-flow metering suits chemical injection in upstream oil and gas, such as inhibitors and methanol, plus polymer and antiscalant dosing in desalination and power plant water treatment. It is also used for catalyst and additive feed in petrochemical units and for test skids. A thermally insulated line should respect the ambient and medium temperature derating given in the datasheet in hot-climate installations.
Information to send with your RFQ
- Existing nameplate or order code.
- Medium, flow range, pressure and temperature.
- Connection type and size.
- Output and fieldbus, supply voltage, hazardous-area marking.
- Certificates and tests required.
Documents and quotation
The Endress+Hauser Technical Information for the Promass A 300 is attached on this page as a datasheet. Send the part number and your duty data and we will confirm configuration, lead time and availability for Oman and the GCC.
Other Models in the Eh Promass Coriolis Range
Seven Star LLC supplies models from the Eh Promass Coriolis range in Oman and the GCC. Compare the related models below and request a quote for the one that matches your application.
| Model | Category | |
|---|---|---|
| Endress+Hauser Promass P 100 Hygienic Coriolis Flowmeter | Flowmeters | View details |
| Endress+Hauser Promass A 100 Low-Flow Coriolis Flowmeter | Flowmeters | View details |
| Endress+Hauser Promass A 300 Coriolis Mass Flowmeter | Flowmeters | You are viewing this model |
| Endress+Hauser Promass E 300 Coriolis Mass Flowmeter | Flowmeters | View details |
| Endress+Hauser Promass F 200 Loop-Powered Coriolis Flowmeter | Flowmeters | View details |
| Endress+Hauser Promass H 300 Corrosion-Resistant Coriolis Meter | Flowmeters | View details |
Datasheets & Documents
- Datasheet Endress+Hauser Promass A 300 Technical Information Download
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About brand
Endress+Hauser makes process measurement instruments for flow, level, pressure, temperature and liquid analysis. Georg H. Endress and Ludwig Hauser started the business in Lörrach, Germany, on 1 February 1953, first selling level meters, and the Endress+Hauser name has been used since 1957. The group is headquartered in Reinach, Switzerland, and has been wholly owned by the Endress family since 1975.
Seven Star LLC is an independent supplier listing Endress+Hauser flowmeters, level and pressure transmitters, temperature assemblies and liquid analysis products for buyers in Oman and the GCC. Instruments are matched from the full order code on the nameplate.
Endress+Hauser company profile
| Origin | Founded in Lörrach, Germany, on 1 February 1953 by the Swiss engineer Georg H. Endress and Ludwig Hauser |
|---|---|
| Headquarters | Endress+Hauser AG, Reinach (Basel-Landschaft), Switzerland |
| Ownership | Family owned; the Endress family has been the sole shareholder since 1975, and a family charter commits the company to stay family owned |
| Size | About 16,500 employees and sales of about EUR 3.7 billion (2023, as reported by the company) |
| Product families | Proline flowmeters, Micropilot and Levelflex radar, Liquiphant switches, Cerabar and Deltabar pressure, iTEMP and iTHERM temperature, Liquiline and Memosens liquid analysis |
Milestones
- 1953: Georg H. Endress and Ludwig Hauser start the business in Lörrach on 1 February, first selling level meters.
- 1957: The Endress+Hauser name comes into use.
- 1975: The Endress family becomes sole shareholder.
- 2023: About 16,500 employees and sales of about EUR 3.7 billion, as reported by the company.
Endress+Hauser product lines
| Line | Measuring principle | Typical use |
|---|---|---|
| Promass F 300, Promass 80F, 83F/84F | Coriolis mass flow | Direct mass flow and density of liquids and gases, hydrocarbon transfer and chemical dosing |
| Promag P 300, P 500, H 300, W 400, W 10, 50P | Electromagnetic flow | Water, wastewater, slurries and other conductive liquids |
| Prowirl F 200, 72F | Vortex flow | Steam, gas and low-viscosity liquids |
| Prosonic Flow 92F, t-mass 65F | Ultrasonic and thermal mass flow | Water lines; compressed air and industrial gases |
| Micropilot FMR62, FMR67, FMR60, FMR10B, FMR20, FMR50, FMR52 | Free-space radar level, 80 GHz and 26 GHz | Tanks, process vessels, silos and open water channels |
| Levelflex FMP51, FMP50, FMP54, FMP55 | Guided wave radar level | Level and interface in vessels, separators and bypass chambers |
| Liquiphant FTL51, Prosonic S FMU90 | Vibronic point level; ultrasonic level | High and low level alarms, pump protection, open channel flow |
| Cerabar PMC71B, PMP51B, PMP71, Deltabar PMD78B, PMD75 | Pressure and differential pressure | Process pressure, hydrostatic level and DP flow |
| iTEMP TMT82, TMT162, iTHERM TM101, TR66, TR10 | Temperature transmitters and thermometers | RTD and thermocouple points with thermowells |
| Liquiline CM444, CM442, Memosens CPS11E, Stamolys reagents | Liquid analysis | pH, ORP, conductivity, dissolved oxygen and nutrient analysis in water treatment and process |
Where Endress+Hauser instruments are used
In Oman and the GCC, Endress+Hauser instruments are common in oil and gas production and processing, refineries and petrochemicals, desalination and water networks, wastewater treatment, power plants and food and beverage plants. Coriolis meters measure hydrocarbon and chemical flows, electromagnetic meters cover water and wastewater, radar transmitters handle tank and silo level, and Liquiline analysers monitor water quality. Proline 300 and 500 flowmeters include Heartbeat Technology for in-situ verification, which reduces the need to remove a meter for checks.
Ordering Endress+Hauser instruments: what we need
The order code on the nameplate (for example PMP71-1QA1S11RDADU) defines every option: measuring range, process connection, materials, output, approvals and display. Send it with the serial number; Endress+Hauser can retrieve the original configuration from the serial number. For a new instrument add the medium, operating and design pressure and temperature, range, line size or tank geometry, process connection, wetted materials, output or protocol (4-20 mA HART, PROFIBUS, FOUNDATION Fieldbus, Modbus) and the hazardous-area approval required. Older models such as Promass 80/83 or Micropilot M are replaced by current Proline or 80 GHz Micropilot devices.
Facts checked against Endress+Hauser company history and product information, October 2026.
Browse Endress+Hauser products by category: Flowmeters, Level Transmitter, Pressure Instrumentation, Temperature, Liquid Analysis Sensors, Liquid Analytical Systems.
FAQ
Questions about the Endress+Hauser Promass A 300 Coriolis Mass Flowmeter
Answers from our engineering team on installation, compatibility and integration.
01What is the maximum pressure of the Promass A 300?
The high-pressure version, ordered with tube material option HB, is rated up to 430.9 bar (6,250 psi). High-pressure devices always include a rupture disk, and clamp connections are limited to 40 bar.
02How does the Promass A 300 differ from the Promass A 100?
Both use the DN 1 to 4 single-tube sensor. The Promass A 300 adds the Proline 300 transmitter with up to three I/Os, touch display, WLAN, Ethernet-APL and SIL options, and its gas accuracy is ±0.35 % instead of ±0.50 %.
03Which hazardous-area protection levels apply to the Promass A 300?
With the Ex options the datasheet gives EPL Gb for DN 1 (Zone 1 in the measuring tube) and Ga/Gb for DN 2 and DN 4 (Zone 0 in the tube). The nameplate and safety instructions govern the final marking.
04What power supply does the Promass A 300 need?
The transmitter runs on DC 24 V ±20 % or on AC 100 to 240 V, 50/60 Hz. Maximum power consumption is 10 W and switch-on current is up to 36 A for less than 5 ms.
05What is the Gas Fraction Handler on the Promass A 300?
It is a software function that checks single-phase flow for gas bubbles in liquids and stabilises flow and density readings when they occur. It is available on the HART, Modbus RS485 and PROFINET versions.


















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