Trolex, one of the leading manufacturers of sensors and sensing systems, has just introduced an in-line version of its vortex gas flow sensor/transmitter.

Designed for in-line flow monitoring of air, gases and vapours in pipelines, the TX5926 and TX5927 models are made to the usual Trolex exacting standards. The two models provide the option of either a 1in or 2in nominal bore and applications for these gas flow sensors range from ventilation systems, cooling systems, and plant protection through to high-accuracy transfer metering, environmental control and monitoring as well as for process extraction plants. They are built for use in power plants, process plants, pharmaceutical production, biogas plants and landfill sites as well as cement manufacture and the mining industry — anywhere where gas flow detection in pipes is required. The new in-line vortex gas flow sensors are certified intrinsically safe to Group I and Group II EURONORM standards for use in potentially explosive atmospheres.

The vortex flow velocity sensing system provides high accuracy, flow measurement free from drift and mechanical deterioration. As the stream of gas passes through the sensing zone, vortices are generated by a transverse strut or ‘Bluff Body’ positioned in the flow path. The vortex frequency is proportional to the flow velocity and this frequency is detected by an ultrasound beam accurately located downstream of the strut. This information is processed by a specially designed software programme to provide a user-configurable information display and a conditioned linear output signal.

Both the TX5926 and TX5927 have programmable information display for zero, span, signal offset, volumetric calculations, engineering units, turndown, damping, display suppression, fault mode, contrast and signal clamp. There are no moving parts on the product and the self-cleaning vortex sensing head gives ultra long-term stability. The units also offer configurable signal turndown and response linearity in true engineering units as well as a volumetric flow calculation facility.

Other features include language display text options, keycode software security protection, simple pushbutton scaling to match on-site parameters and an automatic self test function. Both versions offer rangeable velocity from 0.5m/s to 30m/s. Different output signal versions are available as well as high-pressure versions up to 20bar.