Eldridge Products, Inc.’s innovative new Flow Averaging Tubes (FAT™) provide accurate flow measurement in large pipes and ducts without the expense and complexity of traditional multipoint systems, offering a cost-effective solution for Heating, Ventilation, and Air Conditioning (HVAC) and Variable Air Volume (VAV) applications. They also provide accurate, repeatable readings in applications with very limited upstream straight run.

The Master-Touch FAT™ probes utilize a flow averaging tube to give a stable flow signal in applications where the flow profile is less than ideal, such as downstream of a bend, valve, tee or obstruction. The flow averaging tube has a number of large diameter (0.125”) inlet ports along the length of the upstream impact surface. The impact pressure at each inlet port is averaged inside the tube to create the axial flow through the tube and across our flow sensor. The gas flow then passes back into the main flow stream through the gas return ports located near the flow sensing elements.

Anomalies in the actual flow profile or installations in non-circular ducts may require a C-Factor adjustment for the best accuracy. The velocity impact pressure follows a square root function. Therefore, the average velocity pressure in the FAT™ probe may vary slightly from the average of the velocities at each inlet port. The Master-Touch electronics easily accommodate the C-Factor adjustment.

The Master-Touch MP Series FAT™ probes are now approved for use in hazardous area locations:

	CSA/CUS – For use in hazardous area locations; Class I Group B,C,D; Class II Group E,F,G; CLASS III; Encl Type 4X; Class I Zone I; AEx d IIB+H2 IP66; Ex d IIB+H2 IP66; T2 or T3 or T4 as marked; Ta = 0°C TO 50°C
	ATEX – Ta = 0°C TO 50°C; IP66; Ex d IIB+H2 T4 Gb/EX t IIIC T135°C Db or; Ex d IIB+H2 T3 Gb/EX t IIIC T200°C Db or; Ex d IIB+H2 T2 Gb/EX t IIIC T300°C Db; SIRA 12ATEX1302
	IECEx – For use in hazardous area locations; T2 or T3 or T4 as marked; Ta = 0°C to 50°C;; Ex d IIB+H2 T2…T4 Gb IP66; Ex tD A21 IP66 T135°C…T300°C; IECEx CSA 11.0014
	KOSHA – For use in hazardous area locations; T2 or T3 or T4 as marked; Ta = 0°C TO 50°C; Ex d IIB+H2 T2…T4 Gb IP66; Ex tD A21 IP66 T135°C…T300°C

The remote enclosure is certified for use in Ordinary (Non-Hazardous) area locations:
Type 4X, IP66

Insertion Style

Mounting insertion style tubes in pipes or ducts typically uses tube to pipe compression fittings or flanges (as shown below). “Hot tap” options with ball valve retractor assemblies are also available. Multiple tubes can be used with a Model 9601MP System Control Panel for a grand-averaged output.

Inline Style

Configurations

MP Series FAT™ flowmeters are approved for use in hazardous locations. Series 9100MP-9200MP instruments have an explosion-proof flow transmitter mounted at the point of measurement with the signal processor electronics remotely mounted in a separate, general purpose enclosure. An explosion-proof enclosure for the remote electronics is available as an option. The Series 9700MP-9800MP instruments have all electronics mounted at the point of measurement in an explosion-proof enclosure.

MPNH Series FAT™ flowmeters are designed for installation in non-hazardous environments. They feature 5” x 5” x 4” ABS plastic enclosures. Series 9100MPNH-9200MPNH instruments have the flow transmitter mounted at the point of measurement with the signal processor electronics remotely mounted in a separate enclosure. Series 9800MPNH instruments have integral electronics mounted at the point of measurement.

The connections for input power and output signals for the Model 9200MP and Model 9200MPNH are located in the remote electronics. This configuration uses only a two-wire connection between the flow transmitter and the signal processor. All input and output connections for the Model 9800MP and 9800MPNH are available in the integral electronics enclosure.

As with all Master-Touch thermal mass flowmeters, you get a powerful set of features that includes:

• Tracking of overall gas consumption over a turndown ratio of at least 100:1 with an accuracy of ±[1.0% of Reading +(0.5% + 0.05%/°C of Full Scale)], and repeatability of ±0.2% Full Scale;
• Extensive diagnostics including time and date stamping of maximum and minimum flow rates;
• User-selectable high or low biasing to optimize long term tracking against supplier metering;
  A 2 line, 16 character display for rate, total, and relay status;
• Up to four independent metering ranges, and the ability to switch between the ranges without interrupting your production process; and
• A wide variety of user-selectable engineering units that dynamically convert the flow rate and elapsed total to the new units.

You can control all of these features with the four button touch keypad or via RS232 and RS485 I/O communications using EPICommunicator software. Please see our pages for the MP Series thermal mass flow meters and EPICommunicator for a full description of these features.