Imaging focuses on 3D, colour and simple use

Paul Boughton
The latest imaging technologies are using 3D, colour and improved software to give a much better insight into how processes are operating.

Sick recently won the award for applied machine vision at the Vision Awards in Stuttgart, Germany, with its ColorRanger E camera. This is newest member of the company's 3D camera product line.

The cameras are used as a key vision component by manufacturers and vision integrators worldwide. They solve various inspection tasks by measuring shape, contrast, and surface defects, to ensure product quality and production reliability.

The ColorRanger E expands the inspection possibilities further by also providing high-resolution RGB colour at up to 3072 pixels per channel. With simultaneous 3D and colour information at more than 11kHz, multiple inspections can be performed in parallel at full production speed.

3D imaging is ideal where height, shape, or volume is of importance for the production process. However, to make a complete quality or grading decision, it is often necessary to also consider the colour of the parts produced. This is, for instance, common in grading fruits and vegetables, shape and baking degree verification of baked goods, board grading in the wood industry, quality assurance of electronic assemblies, and fill level and colour verification in the cosmetics and pharmaceutical industries. By considering both 3D and colour, more reliable inspections can be performed which improve product quality and reduce waste (Fig.1).

ColorRanger combines the functionality of a 3D camera and a line-scan colour camera. With SICK's proprietary MultiScan technology, the camera can be configured to provide several measurements at the same time, including 3D shape, laser scatter, colour, and monochrome, according to the exact need of each specific application.

As a result, says SICK, one ColorRanger can replace several other cameras, which reduces the system size as well as the cost for hardware, integration, and maintenance. In addition, since the different measurements come from the same camera system, it is easier to combine data for analysis.

ColorRanger delivers high-quality 3D and multi-linear colour data, including RGB, near IR, and monochrome without IR content, on a gigabit Ethernet communication interface. It has a separate row of pixels for each colour, which give full colour resolution at up to 3072 pixels per channel. The colour quality is ensured by well separated colour filters of high spectral response, on-chip white balancing, and spatially corrected colour channels output. In addition, to eliminate interference from different light sources used for 3D and colour imaging, there is a filter option for light source separation.

Expanded process views

Raytek, a worldwide provider of IR thermometry and maker of the industry-leading ThermoView Ti30 infrared camera, has introduced the Thermoview Pi20 process imager and DataTemp Pi (DTPi) software.

This easy-to-use thermal imaging solution provides an expanded view of process performance in a wide range of industrial applications (Fig.2).

Designed for automated monitoring and control of continuous or stationary targets, the ThermoView Pi20 fixed-mounted process imager provides a process view of thermal images, allowing plant operators to shorten process start-up times and lower production line changeover costs. The camera is paired with the intuitive DTPi software, which minimises or eliminates the long learning curve associated with many process imaging systems.

The ThermoView Pi20 camera and DataTemp Pi software are designed for use in diverse and often rugged industrial settings. During solar module testing, for example, the thermal imaging system allows early detection of defective solar cells. It also enables manufacturers to improve productivity and energy generation from solar modules. In the tobacco industry, the system helps to reduce waste from improperly dried tobacco and prevent fires caused by smouldering tobacco stored in bunkers. The thermal imaging camera and software also detect unquenched clinkers on coke conveyers, and identify hot spots during pressboard production and garbage incineration.

Featuring an IP54 rating, the rugged ThermoView Pi20 camera is offered in two temperature ranges: -40 to 500°C and 200 to 2000°C. For each temperature range, two lens options are available: 21.7° x 16°, or 30° x 22°. The ThermoView Pi20 provides easy networking over long distances using a standard Ethernet interface, which transmits up to 30 frames per second of imaging data from the camera. Additional fibreoptic Ethernet accessories enable Ethernet cable runs beyond 90m, thus eliminating the need to place the PC operating DataTemp Pi software in a hazardous area. These features reduce the user's capital investment costs by eliminating the need for specialised enclosures and expensive industrial computers to survive in a harsh field environment, says the company.

According to Omega, whether used for communications or IR temperature measurement, fibreoptics offer some inherent advantages for measurements in industrial and/or harsh environments: These include: unaffected by electromagnetic interference (EMI) from large motors, transformers, welders and the like; unaffected by radio frequency interference (RFI) from wireless communications and lightning activity; can be positioned in hard-to-reach or view places; can be focused to measure small or precise locations; does not or will not carry electrical current (ideal for explosive hazard locations); fibre cables can be run in existing conduit, cable trays or be strapped onto beams, pipes or conduit (easily installed for expansions or retrofits); and certain cables can handle ambient temperatures to over 300°C - and higher with air or water purging.

As such, the company says that fibreoptic thermometers have proven invaluable in measuring temperatures in basic metals and glass productions as well as in the initial hot forming processes for such materials. Boiler burner flames and tube temperatures as well as critical turbine areas are typical applications in power generation operations. Rolling lines in steel and other fabricated metal plants also pose harsh conditions which are well handled by fibreoptics.

Sintering operations

Other typical applications include furnaces of all sorts, sintering operations, ovens and kilns. Automated welding, brazing and annealing equipment often generate large electrical fields which can disturb conventional sensors.

Meanwhile IFM Electronic's range of temperature sensors are designed to meet a number of requirements: precise temperature measurement by Pt1000 sensor element; integrated or separate control monitors selectable; modular concept - tailor-made for every application; optional fittings for variable process connection; and robust mechanics with high resistance to vibration and shock

The company's sensors are all based on a Pt1000 resistor. The measured temperature value corresponds to a change in resistance and is converted into an electrical analogue signal. The microprocessor and the display make process adjustment much easier. The user can set the values for the switch points, hysteresis and measuring range by means of programming buttons even without the system temperature being applied. This enables installation and setup of the system within a few minutes.

Film technology is used for the electronic circuitry. A flexible, temperature-resistant and extremely resistant polyimide film is used as carrier of the SMD components. Together with a special potting method an extreme shock and vibration resistance is achieved.

TC, a leading manufacturer and supplier of temperature sensors and related instrumentation and accessories, offers an extensive range of temperature measuring products including mineral insulated thermocouples (from 0.25mm diameter), general thermocouples, resistance thermometers (RTD, Pt100), thermocouple connectors, thermocouple cables (single and multipair), temperature controllers, dataloggers, and hand-held instrumentation.

Thermocouples and Pt100 sensors can be custom designed and manufactured to exact requirements within a few days. Alternatively, the company also has a massive range of temperature sensors in stock ready for despatch.

The company's practical international reference work Thermocouple and Resistance Thermometry is available now and is completely free. It includes: an illustrated 37000 word explanation on the theory of temperature measurement; extensive application data; a full list of hardware to suit all applications; international reference tables and tolerances; international colour codes; international standards; and comprehensive illustrations

Multichannel optical pyrometers

Prague Precision's multichannel optical pyrometer is designed for continuous and automatic temperature measurement of molten metals and other hot materials. The determination of temperature is based on an original method of signal processing which eliminates negative disturbances that may occur during the temperature measurement. Its resistant mechanical construction guarantees a reliable performance under hard industrial conditions.

The computer controlled operation enables to incorporate the optical pyrometer as an integral part of central control systems.

The company says that this original method of signal processing means that its pyrometer can be used in situations where one- or two-channel pyrometers would not be able to give reliable results. These include:

- Measurement of unstable or moving objects such molten metals in steelworks, blast furnaces and foundries;

Measurement of objects with islands of different temperature and/or emissivity on their surface, for example slag islands;

- Measurement in environments with varying observation conditions created by, for example, dust and smoke gusts and other obstacles to clear observation, intensive light sources, and decreasing transmittance of the entrance window;

- Measurement in technological plants with aggressive environments including heat emission, vibrations, dust and hot metal drops; and

- Measurement which may be influenced by unintentional and/or intentional interference with the pyrometer operation.

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