Editor’s choice

snow, high and low temperatures and wind. They can also be used to detect a poor target in front of a good reference target. Radar sensors can be hidden behind a plastic facia panel or in a plastic box with negligible effect in performance.

millimetres, or still detect a difference of less than 10 mm at a range of 250m. The small diameter, intense light spot makes them easy to align and relatively immune to target colour. Mirrored surfaces can be difficult to detect, if they reflect the light away from the sensor, not back to it. In order for laser sensors to be eye safe they

have very little light energy. This energy is concentrated in a very small area, so anything which disperses that energy will affect the performance, i.e. smoke, steam, rain or dirty lenses. As Laser beams are so narrow, vibration can severely affect the sensor by moving the detection spot off of its target. At 1m range a 0.5° angular vibration will move the spot 9mm.

temperature compensation, as the speed of sound changes with temperature. As the speed of sound also changes with pressure avoid using ultrasonic sensors where the pressure changes. Ultrasonic waveguides often have a narrow slit in them to avoid pressure changes. An ultrasonic sensor relies on a moving

transducer to create and receive a sound wave in order to detect an object. Anything that can interfere with this transducer movement or the sound wave will affect the sensor performance. For example, product labels, grease or a build-up of snow will interfere with the transducer movement, high winds and torrential rain can distort the sound wave.

LASER Laser sensors use a single frequency and phase of light. This creates a narrow intense beam of light that does not spread out and disperse as most light does. This makes them ideal for detecting small objects at relatively large distances, or the absence of small features, like a thread missing from a hole. Laser sensors can also measure tiny height differences such as thousandths of a millimetre at short distances of a few hundred

Instrumentation Monthly October 2020

FIBRE-OPTIC Fibre-optic sensors used to be the saviour of people wanting to detect something in a small space, now miniaturisation has produced some very small sensors. Fibre-optic sensors are still the go-to option for very small spaces. Fibres can be routed into the heart of a machine with the sensor mounted on the outside where it is easily accessible. Various fibres can withstand hostile environments, such as high vibration, extreme heat, wet, corrosive, explosive and electrically noisy environments. The disadvantages of fibre-optic sensing are that you have to buy a fibre and a sensor, and that they have relatively short range.

RADAR Radar sensors use a frequency modulated continuous wave in the GHz frequency band to detect both stationary and moving targets. Their field of view can typically vary from 10° to 90° and ranges from 3.5m to 100m are available. The target must contain metal, water or a similar high-dielectric material. Radar sensors are particularly suited to detecting stationary or moving vehicles in rain,

GUIDED MICROWAVE Guided Microwave is used in liquid level measurement. An electromagnetic wave is emitted along the probe, when the wave reaches the medium, it is partially reflected due to the different level of permittivity in comparison to the surrounding air. The electromagnetic wave is recaptured by the sensor and the distance to the surface of the liquid can be calculated from the elapsed time. Foams on liquids can be reliably filtered out to give a true liquid level measurement. If the guided microwave sensor is used in a metal container, its interior wall functions as an outer conductor for the electromagnetic wave. In non-metallic containers, a coaxial tube is used to replace the outer conductor. Guided microwave sensors are generally used in

the following applications: monitoring of coolants and lubricants in machine tools; monitoring of cleaning solutions and cleaning agents in mechanical engineering; filling systems in automotive production chains; and level measurement in industrial processes subject to difficult environmental conditions.

MEASURING SENSORS WITH I/O LINK I/O Link has many benefits, such as automatic reprogramming of replacement sensors and data collection. It also brings a whole new level of options to measurement sensors. Typically measurement sensors used to fall into one of three categories. 1) Measurement with discrete switching points. 2) Measurement with analogue (0-10v or 0, 4-20mA) outputs. 3) Measurement with data output. Measuring sensors with I/O Link now often

incorporate categories 1 and 2 with data I/O. One sensor can now perform multiple tasks, discrete outputs for position limits or alarms, analogue outputs for indication, and data output for highest resolution control or analysis. I/O Link enables on-the-fly programming of set

points, analogue windows etc. giving greater flexibility in changing applications. I/O Link also enables condition based monitoring, facilitating local logic based control and OEE (Overall Equipment Effectiveness). Turck Banner have the widest range of sensors in the industry, Turck and Banner have been at the forefront of sensor technology for over 50 years. No matter what kind of object or material has to be detected or inspected, or what-ever requirement has to be met, Turck and Banner have the right products for every application. Furthermore, they provide unique and comprehensive solutions, quickly, flexibly and reliably, because both companies have never ceased to concentrate on their core strengths.

Turck Banner 11

Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74