Endress+Hauser Promass A 100 Low-Flow Coriolis Flowmeter

Promass A 100 Coriolis flowmeter for the smallest liquid and gas flows

The Endress+Hauser Promass A 100 is a Coriolis mass flowmeter designed for very small quantities. Its single bent measuring tube is self-draining and comes in only three sizes: DN 1, DN 2 and DN 4, with full-scale values of 20, 100 and 450 kg/h of liquid. That makes the Promass A 100 the usual choice for dosing, additive injection, catalyst feed, laboratory and pilot plants, and test rigs where larger Coriolis sensors would sit at the very bottom of their range. Seven Star LLC supplies it in Oman and the GCC as an independent supplier in Muscat.

It measures mass flow, density and temperature directly and derives volume flow, corrected volume flow, reference density and concentration. Unlike many small-bore meters it handles gases as well as liquids, and the process pressure rating reaches 400 bar with the right connection.

What the Promass A 100 model name means

• Promass A is the high-precision single-tube sensor for minimum flow rates.
• 100 is the ultra-compact transmitter generation shared with the Promass P 100, with HART or fieldbus output and an optional local display.
• The nominal size is selected through the order code: DN 1 (1/24 in), DN 2 (1/12 in) or DN 4 (1/8 in).

Wetted materials, process connection, housing, output and approvals are all selected by order code. A nameplate photo of an existing unit is the fastest way for us to match a replacement.

Promass A 100 technical specifications

How the Promass A 100 measures tiny flows accurately

A single tube is excited at its resonance frequency while a counter-mass vibrates against it. Fluid moving through the tube creates a phase shift between the inlet and outlet pickups that is proportional to mass flow, and the resonance frequency itself gives density. Because only one thin tube is involved, the measuring tube has little volume and responds quickly to changes in dosing rate.

At these low flows, zero stability is the figure that decides accuracy. The datasheet quotes 0.0010 kg/h for DN 1, 0.0050 kg/h for DN 2 and 0.0225 kg/h for DN 4, so the meter should be zeroed with the line full and at rest under process conditions. If the process temperature differs from the temperature at zeroing, an additional error of roughly 0.0002 % of full scale per degree Celsius applies.

Gas measurement with the Promass A 100

For gases the usable full scale depends on gas density and speed of sound and is limited by a constant of 32 kg/m³ for all three sizes. The datasheet gives a formula, and the lower of the two results applies, so gas ranges are always smaller than the liquid values above. Send us gas composition, pressure and temperature and we can check the range with the manufacturer sizing tool results you hold.

Pressure safety: burst rating, purge and rupture disk

The sensor housing is filled with dry nitrogen and contains the process fluid if a tube fails. For high gas pressures, or where the process pressure exceeds two thirds of the housing burst rating, a rupture disk with a trigger pressure of 10 to 15 bar is recommended; it cannot be combined with the separate heating jacket. Purge connections allow gas detection but the purge pressure must not exceed 5 bar, and they should only be opened if the housing can be refilled at once with a dry inert gas.

Process connections available on the Promass A 100

Standard options are EN 1092-1 (DIN 2501 and DIN 2512N), ASME B16.5 and JIS B2220 flanges, Tri-Clamp (DIN 11866 series C) and 4-VCO-4 couplings. VCO connections can be fitted with adapters to flanges, Swagelok or NPT. Surface roughness options and 3-A, FDA and food-contact conformity apply only to correspondingly ordered versions.

Hazardous-area and approval notes for the Promass A 100

Certified hazardous-area versions are covered by separate Endress+Hauser safety instruction documents (XA), listed in the datasheet for ATEX/IECEx Ex i and Ex nA, cCSAus intrinsically safe, INMETRO and NEPSI. The marking must be matched to the nameplate and to your zone classification before ordering, so state it in your enquiry.

Selection checklist for the Promass A 100

• Fluid or gas, density and compressibility; for gases, pressure and speed of sound.
• Maximum and minimum flow in kg/h: pick the size where normal flow is about 20 to 50 % of full scale.
• Pressure class and connection type, including VCO or flange adapters.
• Tube material: 904L for general chemicals or Alloy C22 for aggressive media.
• Rupture disk, purge connection, heating jacket, or insulation needs.
• Output, power supply and hazardous-area marking.

Installation and commissioning of the Promass A 100

Follow the orientation guidance in the datasheet for your fluid, whether liquid or gas, and keep the measuring tube full, avoid vibration sources next to the sensor and use a stable support. Tighten VCO fittings with new gaskets and check for leaks at working pressure. Commissioning is short through the local display or integrated web server, and Heartbeat Technology can verify the device without removing it.

Typical applications of the Promass A 100 in Oman and the GCC

In the region, small Coriolis meters are used for chemical dosing in water treatment and desalination, corrosion-inhibitor and demulsifier injection on oil and gas facilities, fuel and additive tests in laboratories, and sampling or blending skids at petrochemical sites. For outdoor skids the housing rating handles dust and humidity, and a weather cover or shade helps avoid direct sun on the transmitter.

Information to send with your RFQ

• Nameplate photo or complete order code of the existing meter.
• Fluid or gas, flow range, operating pressure and temperature.
• Connection type and size, and pipe or tubing standard.
• Output, power supply and zone marking.
• Certificates required with the shipment.

Documents and quotation

The Endress+Hauser Technical Information for the Promass A 100 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.