Master-Touch Series 8600-8700MPNH GEN Inline Flow Meters

Master-Touch Series 8600-8700MPNH GEN Inline Flow Meters are rugged, cleanable, thermal mass flow sensors. These units consist of a sensor assembly which utilizes two RTD (Resistance Temperature Detector) sensing elements. The sensors feature construction of reference grade platinum, ceramic, glass, and stainless steel. Two platinum resistance sensors are built up upon the ceramic substrate and then receive a thin glass coating.

The assembly then slips into a stainless-steel sheath for corrosion and abrasion resistance. The sensor assembly is large, rugged, and relatively insensitive to dirt buildup. During operation, the temperature sensor constantly measures the ambient temperature of the gas and maintains a reference resistance on one side of a bridge circuit.

The second sensor undergoes self-heating, using a temperature sensor and bridge circuitry, to a constant temperature above that of the gas stream. The bridge maintains overheat temperature and counterbalances the temperature effects through Eldridge Product Inc.'s (EPI) proprietary temperature compensation techniques.

• accuracy: ± 1% of reading + 0.5% of full scale + GTC
• repeatability: ± 0.2% of full scale
• sensor response time: 1 second to 63% of final value
• gas temperature coefficient (GTC): 0.02% full scale/˚C
• gas pressure effect: negligible over ±  50% of factory calibration pressure
• certifications: CE, CSA/CUS - Class 2252-03 & 2252-83, CSA Enclosures Type 4X, IP66

Master-Touch 8600-8700 Series Flow Meters

Master-Touch inline style thermal mass flow meters include a flow section that matches the user’s flow conduit and then plumbs directly into the process line. The sensing elements mount directly in the flow section for exposure to the process gas. The inline style thermal mass flow meters are available in sizes from 1/4" pipe through 4" pipe or tube. They feature a variety of options such as MNPT ends, tube end fittings, butt weld ends, flanged end configurations, etc. as per application requirement.

Pipe sizes more than 4" typically require insertion style thermal mass flow meters. Integral style thermal mass flow meters have all the electrical components and connections within one enclosure. This enclosure offers ratings for non-hazardous environments. Furthermore, the enclosure mounts directly to the inline flow section or to the insertion probe assembly at the point of measurement. The enclosure includes all electrical connections as well as the linearizing electronics and the display / keypad assembly.

Thermal Mass Flow Meters for Gases

Thermal mass flow meters use the principle of convective heat transfer to directly measure mass flow. EPI’s proprietary thermal mass flow sensors use two ratiometrically-match, reference-grade platinum Resistance Temperature Detectors (RTDs). In addition, the platinum sensing element wire is in a 316 Stainless Steel sheath or, if necessary, a Hastelloy C sheath. Our microcontroller smart sensor technology preferentially heats one RTD. Then the other RTD acts as the temperature reference.

The process gas flow dissipates heat from the first RTD, causing an increase in the power necessary to maintain a balance between the RTDs. This increase directly relates to the gas molecular rate of flow. Our sensors are temperature compensated for a wide process gas temperature range and are insensitive to pressure changes, so the output signal is a true mass flow rate signal.