Analytical Instrumentation & Environmental Monitoring


Dust emission monitoring by laser

November 2000 Analytical Instrumentation & Environmental Monitoring

One of the main causes of atmospheric pollution is uncontrolled emission of dust. Classified industries are required to fit an approved dust emission measurement system such as that offered by Oldham.

The Oldham Observer EP 1000 is based on the principle of laser beam retrodiffusion by dust particles. Pointed towards the dust-bearing atmosphere, the laser beam is reflected by the suspended particles back towards the source, providing an indication of dust concentration. The amount of reflected light is used to determine dust concentration in the atmosphere. Measurement is instantaneous and permanently recorded.

Figure 1. The Oldham Observer EP 1000 dust monitor
Figure 1. The Oldham Observer EP 1000 dust monitor

The EP 1000 uses light reflection (instead of absorption as in other equipment) and has the ability to measure very low concentrations with no zero drift. It is relatively insensitive to water droplets, flowrate and particle temperature. The unit features excellent signal linearity, especially at very low concentrations.

The laser transmitter is modulated, only the portion of the detected light that exhibits modulation identical to transmitting laser's modulation is measured as reflected light. This makes the dust monitor essentially immune to interference from any spurious light sources. The detector is relatively insensitive to water droplets and it has a built-in protection from dust penetration. This is implemented by means of a positive air pressure (from an air blower) and an optional shutter. These features, together with its insensitivity to temperature variations make it a reliable instrument.

The detector is housed in an easy to install polyurethane box, only one side of which has to be mounted into the stack. The unreflected portion of the transmitted laser beam enters a light trap, which is mounted on the stack, opposing the sensor/transmitter installation. The sensor requires no special alignment.

Figure 2. Accessories: air blower, chart recorder, remote keyboard and light traps
Figure 2. Accessories: air blower, chart recorder, remote keyboard and light traps

Several selectable ranges of operation are available, the device, which has a linear response characteristic, may be run continuously or be used for instantaneous measurements. Outputs available are 2 to 20 mA, RS485, RS422 and Modbus. The Oldham Observer EP1000 has a setpoint overshoot alarm and is specified to operate between -25 and +55°C.



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Oxygen measurement in beverages
Analytical Instrumentation & Environmental Monitoring
[Sponsored] Anton Paar offers a complete range of oxygen measurement instruments for total package oxygen (TPO) measurements, at-line quality control (QC), and in-process monitoring. These instruments help beverage manufacturers achieve accurate, reliable oxygen control at every stage of production.

Read more...
Analysers achieve OIML R140/MID accuracy class A certification
Analytical Instrumentation & Environmental Monitoring
Qmicro by Sensirion has received the OIML R140/MID accuracy class A certificate No. TC12537 for its DynamiQ-X GC analysers for the analysis of natural gas and natural gas blended with hydrogen.

Read more...
Sustainable water management
Wearcheck Analytical Instrumentation & Environmental Monitoring
Water sustainability is critical for the future wellbeing of people, land and marine ecosystems, and socio-economic development. WearCheck Water provides a range of water analysis techniques to determine water quality for various sectors, including mining, agriculture, domestic and the healthcare industry.”

Read more...
Biofilm monitoring system
Instek Control Analytical Instrumentation & Environmental Monitoring
Alvim, through Instek Controls, provides innovative, high-tech solutions for biofilm and biofouling monitoring in industrial plants.

Read more...
WearCheck Water earns AdBlue/DEF analysis accreditation
Wearcheck Analytical Instrumentation & Environmental Monitoring
WearCheck Water recently became the first laboratory in Africa to be officially ISO17025 accredited to test AdBlue diesel exhaust fluid by the South African National Accreditation System.

Read more...
Streamlining strain gauge load cell integration
Vepac Electronics Analytical Instrumentation & Environmental Monitoring
Vepac’s data acquisition hardware provides an efficient and effective all-in-one solution for customers looking to simplify, enhance and optimise their strain gauge load cell systems.

Read more...
Oxygen measurement in beverages
Anton Paar Analytical Instrumentation & Environmental Monitoring
[Sponsored] Anton Paar offers a complete range of oxygen measurement instruments for total package oxygen (TPO) measurements, at-line quality control (QC), and in-process monitoring. These instruments help beverage manufacturers achieve accurate, reliable oxygen control at every stage of production.

Read more...
Sensors and controls for food, beverage and pharmaceutical
Instek Control Analytical Instrumentation & Environmental Monitoring
Included in Instek Control’s range is Anderson-Negele, which has adopted ‘Hygienic By Design’ as its guiding principle, with a particular focus on meeting the stringent regulatory requirements found in industries such as dairy, brewery or pharmaceutical.

Read more...
Vertical labelling of test tubes in clinical laboratories
Omron Electronics Analytical Instrumentation & Environmental Monitoring
Werfen has implemented a new automated machine for the supply of reagents to drug toxicology laboratories, built by MACCO in collaboration with OMRON and Marini Pandolfi. It uses OMRON SCARA robots and advanced vision systems to ensure reagent quality through vertical handling and labelling process of test tubes.

Read more...
Keeping a close eye on product quality and purity
Endress+Hauser South Africa Analytical Instrumentation & Environmental Monitoring
Colour measurements are necessary in many processes to avoid product losses and ensure safe production and batching.

Read more...