VisGuardVisGuardVisGuardVisGuardVisGuardVisGuard
VisGuard
VisGuard
VisGuard
VisGuard
VisGuard
VisGuard
VisGuard

VisGuard

The Sigrist VisGuard is your partner in the safety and monitoring of road and rail tunnels. To ensure safety in a critical tunnel application you need to have dependable information on 

  • Visibility measurement 
  • Ventilation control 
  • Early fire/smoke detection in road and rail tunnels 
  • Dust concentration in air 
  • Detection of oil mist 

Visibility, CO concentration, and sometimes NO concentration are vital criteria for assessing air quality in road tunnels. These parameters are used for controlling the ventilation system in order to minimise energy consumption and also for closing down the tunnel whenever pre-established safety limits are exceeded.  

The  VisGuard is available in different versions:  In-situ, Extractive or Mini-extractive Installation  

Category:

Description

Technical Description – Sigrist VisGuard

Visibility concentration, smoke and fire detections in tunnels

The Sigrist VisGuard is your partner in the safety and monitoring of road and rail tunnels. To ensure safety in a critical tunnel application you need to have dependable information on

  • Visibility measurement
  • Ventilation control
  • Early fire/smoke detection in road and rail tunnels
  • Dust concentration in air
  • Detection of oil mist

Visibility, CO concentration, and sometimes NO concentration are vital criteria for assessing air quality in road tunnels. These parameters are used for controlling the ventilation system in order to minimise energy consumption and also for closing the tunnel whenever pre-established safety limits are exceeded.

The VisGuard is available in different versions:  In-situ, Extractive or Mini-extractive Installation

VisGuard

A Closer Look

Visibility is stated in the form of an extinction coefficient that corresponds to the light attenuation caused by air pollution. It is possible to use either the level of transmitted light or scattered light as basis of the measuring system, because most of the light attenuation is caused by scatter effects.

The Sigrist VisGuard measures the scattered light intensity of a sample drawn into the instrument from the tunnel. This configuration permits extremely simple installation without time-consuming adjustment, reliable checking and correction of the zero and reference points without ambient air effects, and the ability to carry out measurement either inside or outside the tunnel cavity. An optional heater at the sample inlet effectively eliminates any troublesome mist effects.

To achieve the earliest possible detection of hot or cold fires producing smoke, a second current output or a limit contact (with a higher threshold value) can be used which is independent of measuring range 4-20mA output. This system opens up new possibilities for improving tunnel safety.

The tunnel air is extracted by a blower and carried through the flow cell. In the in-situ version the blower is integrated in the sensor. For the extractive arrangement, separate fans are used because more power is required. The blower also feeds filtered purge air to the flow cell, thus enveloping the sample in a protective shroud of clean purge air. This effectively keeps the optics clean and minimizes drift caused by fouling.

The  VisGuard is available in different versions:  In-situ, Extractive or Mini-extractive Installation

Flexible integration into your monitoring system 

Integration is simple with the following options:

  • SIREL control unit with 4 – 20 mA signal output and 2 relays contacts
  • SIBUS multichannel control unit to connect up to 8 instruments (also units from other manufacturers to measure wind speed, COx, NOx monitors, as required )
  • SIPORT PB for direct integration into a Profibus communication network

Easy calibration using a calibration rod 

Calibration is performed very quickly, and simply with no tool or consumables:

  • The VisGuard uses a highly stable and homogeneous optical calibration unit to performs the calibration automatically, and in less than 30 seconds
  • Fast and reliable calibration method without any tools
  • Zero point filter optionally available
  • Works independent from the current air quality existing in the tunnel

Easy maintenance 

Due to the limited time available for maintenance of tunnel sensors, the VisGuard maintenance is very simple easy to ensure reliable data:

  • No tools required for maintenance tasks
  • Quick release enclosures for quick access to the various parts
  • Maintenance interval is only once per year
  • Maximum time needed is 10 minutes per sensor
  • Changing of the filter is only required every 1 to 5 years (depending on the soiling)
  • LED light-source means no need for lamp changing
VisGuard

Data Sheet - VisGuard

VisGuard Mounting

Hover Box Element

VisGuard 2 In-situ

Hover Box Element

VisGuard and Extractive

Hover Box Element

Sampling VisGuard In-situ

Hover Box Element

Visibility in Road Tunnel

Hover Box Element

Road Tunnel

Hover Box Element

Calibration Certificate

Hover Box Element

PROFIBUS Certificate

Hover Box Element

Sigrist Communication Software

Vx29 is the current software controlling communication between the analyser and the SICON.

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The control unit SICON uses state-of-the-art touch screen technology with colour display. It allows simple operation using logical menu guidance. The user can select how results are displayed, either as plain values, graphs or historical data, including the indication of system and alarm status.

The control unit SICON offers all possibilities of full system integration using various interface options. A SD card is standard and can be used for data logging with almost unlimited storage capacity.

The SICON is available as a control unit for a single instrument, or the SICON M Control Unit which allows simple operation of several instruments up to a maximum of 8 measuring channels.

SICON

SICON

The control unit SICON uses state-of-the-art touch screen technology with colour display. It allows simple operation using logical menu guidance. The user can select how results are displayed, either as plain values, graphs or historical data, including the indication of system and alarm status.

The control unit SICON offers all possibilities of full system integration using various interface options. A SD card is standard and can be used for data logging with almost unlimited storage capacity.

The SICON is available as a control unit for a single instrument, or the SICON M Control Unit which allows simple operation of several instruments up to a maximum of 8 measuring channels.

Sigrist SIPORT 2

The SIPORT 2 offers a low-cost connection a signal interface between the VisGuard and your monitoring system.

The SIPORT 2 can be configured to provide:

  • Module StromRel: 2 x 4-20 mA and 3 x semiconductor relays
  • Module Profibus DP interface
  • Module Modbus RTU interface with repeater

A Closer Look

FireGuard
FireGuard