FTB690-Series

Supported Applications

The Omega FTB690 Series (also referenced as the TM Series) comprises economical PVC turbine flowmeters designed for measuring water and other chemicals compatible with wetted components. These meters provide local digital indication of flow rate, cumulative total, and batch total. The series is explicitly noted as not legal for trade applications.

Key operational constraints include sensitivity to electrical noise; the manual advises against operation within one to two inches of electric motors or other sources of electronic interference. Additionally, these products are not designed for human applications.

Operating Conditions & Performance

The series is rated for fluids with a viscosity equivalent to water (1 centistoke). Meters equipped with the display can be used for fluids up to 100 centistokes when field calibration is applied. The operational temperature range is 0 to 60°C (32 to 140°F), and storage temperatures are specified from -40 to 70°C (-40 to 158°F).

Performance specifications include an accuracy of ±3% rdg, with repeatability of ±0.1%. For display models operating in the extended low flow range, accuracy is rated at ±5.0% rdg. The pressure rating is 150 psig (10.3 bar), with a maximum burst pressure limit of 225 psi.

Flow ranges vary by meter size:

• 1/2 inch: 1 to 10 GPM (3.8 to 38 LPM)
• 3/4 inch: 2 to 20 GPM (7.6 to 76 LPM)
• 1 inch: 5 to 50 GPM (19 to 190 LPM)
• 1-1/2 inch: 10 to 100 GPM (38 to 380 LPM)
• 2 inch: 20 to 200 GPM (76 to 760 LPM)
• 3 inch: 40 to 400 GPM (151 to 1514 LPM)
• 4 inch: 60 to 600 GPM (227 to 2271 LPM)

Variance in Minimum Flowrates by Size

The family manual provides minimum flowrate thresholds that differ from the standard operating ranges listed above:

• 1/2 inch meter: 1 GPM (3.8 LPM)
• 3/4 inch meter: 2 GPM (7.5 LPM)
• 1 inch meter: 5 GPM (18.9 LPM)
• 1-1/2 inch meter: 10 GPM (37.9 LPM)
• 2 inch meter: 20 GPM (75 LPM)

Configuration Options

The series offers configurable output options and housing styles to suit different installation needs.

>Housing Materials:PVC construction for the main body. Wetted components include ceramic journal bearings (96% alumina), tungsten carbide shaft, PVDF rotor and supports, and 316 SS retaining rings.
• Process Connections:Available in Sch. 80 NPT fittings or flanged configurations for sizes ranging from 1/2 inch to 4 inches.
• Display Options:The standard configuration features a large 6-digit LCD with floating decimal, powered by two 3V lithium batteries providing up to 5 years of use. The display shows flow rate, batch total, and cumulative total (0.01 to 999,999).
• Signal Output Options:An optional pulse output module replaces the local display. This option provides an open collector sinking signal compatible with 9 to 35 Vdc excitation.

Key Product Differences

The series distinguishes between models based on connection type and size, as well as the presence of a display or pulse output module. Model numbers follow the pattern TM. For example:

• NPT Mount Turbine: Models such as TM05NQ9GMA (1/2 inch) through TM40NQ9GME (4 inch).
• Flanged Turbine: Available for 3-inch and 4-inch sizes, designated with an 'F' in the connection code (e.g., TM30FQ9GME, TM40FQ9GME).

To configure a unit with a pulse output module instead of the display, add the suffix '-P' to the model number. This option incurs no additional cost.