FMG980-Series

Supported Applications

The Omega FMG980 Series consists of fixed depth insertion electromagnetic flowmeters designed for measuring conductive liquids in pipes ranging from 1" to 12". These meters are engineered for difficult applications involving changing viscosities and pulsating flows, such as those driven by air-driven diaphragm pumps. With no moving parts, the series is suitable for 'dirty' applications where debris would foul mechanical meters.

In chemical injection or fertigation scenarios, installation guidelines specify placing the meter upstream of the chemical line or far enough downstream to allow complete fluid mixing before measurement. The sensors are not designed for human applications and should not be installed downstream of a boiler feedwater pump due to potential exposure to excessive pressure and temperature.

Operating Conditions & Performance

The FMG980 Series operates within an ambient temperature range of 0° to 160° F (-17° to 72° C). Process fluid temperatures vary by material: Brass/SS models support 32° to 200° F (0° to 93° C), while PVC models are rated for 32° to 130° F (0° to 55° C) @ 0 psi. Pressure ratings correspond to the wetted material, with Brass/SS rated at 200 psi (13.8 bar) and PVC rated at 150 psi (10 bar) @ 75° F.

Performance specifications include a flow velocity range of 0.28 - 20 ft/sec (0.08 - 6.09 m/sec) with a minimum conductivity requirement of 20 microSiemens/cm. Calibration accuracy is specified as +/- 1% of full scale. The series features software-based empty pipe detection that defaults to zero flow.

Power and Output

• Full Power: 12 - 25 Vdc, 250 mA
• Low Power: 12 - 25 Vdc, 40 mA average with 250 mA peaks (suitable for external battery/solar operation)
• Pulse Output: Square wave pulse, opto isolated, 550 Hz @ 20 ft/sec
• Analog Options: Current sinking pulse output or 4 to 20 mA analog via compatible transmitters (e.g., FMG-1000-MAW)

Configuration Options

The series offers a modular design with configurable wetted materials, housing options, and output configurations. Fixed depth insertion requires special fittings for installation to ensure correct sensor placement.

Materials of Construction

• Mechanical Body: 316 SS, Brass, or PVC
• Electrodes: Hastelloy®
• Electrode Cap: PVDF
• O-Ring: EPDM standard (FKM optional)
• Housing: Cast powder-coated aluminum with NEMA 4X (IP66) enclosure rating

Pipe Sizes and Fittings

The series covers pipe sizes from 1" to 12", divided into three sensor families based on diameter:

• FMG981 Series: For 1" to 3" fittings (Brass, PVC, or 316 SS)
• FMG982 Series: For 4" to 10" fittings (Brass, PVC, or 316 SS)
• FMG983 Series: For 12" fittings (Brass, PVC, or 316 SS)

Installation requires specific fittings sold separately, including Bronze Sweat/NPT/Saddle/Weld/Braze, Stainless Tee/Weld, Carbon Steel Tee/Weld, Ductile Iron Saddle, and PVC Tee/Saddle configurations.

Key Product Differences

The FMG980 Series distinguishes models by pipe size range and wetted material. Model numbers follow the pattern FMG98X-MaterialCode, where X denotes the size group (1, 2, or 3) and MaterialCode indicates B for Brass, P for PVC, or S for 316 SS.

Variants with an integrated display are indicated by a model number suffix of 'M' (e.g., FMG981M-B). These models include the sensor mounted directly on the housing. For applications requiring remote monitoring without a built-in display, the series supports current-sinking pulse outputs that can be fed directly to programmable controllers or combined with wall-mounted rate and total indicators such as the FMG980-W.

Optional features available for specific configurations include reverse flow output and immersibility. Accessories include fitting caps corresponding to the material type: Brass (FMG980-BCAP), PVC (FMG980-PCAP), or 316 SS (FMG980-SCAP).