VIPA

VIPA provides a dependable solution to the requirement for stand alone visibility monitoring in the tunnel environment.

Provided with a power supply (24vdc) VIPA can be controlled and interrogated via serial link (RS232/485) to a PC (local or remote), or alternatively it can be connected to an Operator Interface (OI) which will provide power and the usual wide range of output options expected.

Like the AIRFLOW, VIPA can also be used as an “add on” to either VCOM or NOVA. Connection with either of these analysers (via a single cable) allows VIPA to utilize their power supply and also their output and interface options.

The analyser consists of a transmitter head (Tx) and receiver head (Rx) mounted 6m apart on the tunnel wall or ceiling. The Tx emits a visible (green light) beam which makes a single pass across the 6m open path to the Rx. The transmitted beam is pulsed at a fixed frequency so that the Rx can differentiate between the emitted energy from the Tx and any stray radiated energy in the ambient tunnel environment.

When it arrives at the Rx the visible light beam is collected by an optical bench and processed for opacity in transmission. All signal processing is performed within the Rx and the measurement reading and all diagnostic data are then exported via serial link (RS232/485). This allows the diversity of configuration described earlier.

Use of the established visible transmission technique for the determination of visibility ensures an accurate and reliable measurement at all times.

Used in conjunction with either VCOM, NOVA, or an OI, the VIPA can offer a diverse range of data presentation including 4-20mA outputs, relay contacts, serial comms (RS485/232) and a variety of different bus interfaces including ModBus, Profibus, DeviceNet, Ethernet etc.

A wide variety of diagnostic parameters and intelligent software routines, combined by with practical considerations such as adjustable dual plane mounting brackets and quick release sight tubes, all contribute towards and instrument that is easy to install, commission, operate and service.