| Pressure sensors for pneumatic and hydraulic applications |
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The demands placed on pressure sensors employed within the machine engineering sector for the measurement of hydraulic and pneumatic pressure are high. Which requirements they should meet and what a sensor specialist has to say on the matter are explained |
The pressure of a gas or a liquid is a key magnitude during the operation of many machines and facilities. In the process automation sector the pressure level is normally transmitted to the controller as an analogue value, however in the majority of applications within the machine engineering sector it is of interest whether a particular limit value has been exceeded or not.
The required switch-point accuracy generally lies around one percent of the end value. Furthermore, the choice of higher accuracy on grounds of reducing variants also proves an important criteria in pursuit of cost reduction. Thus the same sensors can be employed for different measurement ranges. However there are further requirements: the installation of the sensors should be simple, quick and preferably not require the use of an additional mounting adaptor. Here a versatile device that can be read from the front and from above according to the different positions of the machine’s pressure connection is of advantage.
In addition to their function as switches, pressure sensors are often used to replace manoscopes. Therefore they need to be easy to read and to display the adjacent pressure with sufficient accuracy. An important consideration in the design of a pressure sensor is its ease of operation. It should be easy to operate, preferably without the use of tools, whereby false operation has to be categorically ruled out.
Turck’s answer to these requirements is the new pressure sensor series PS400/ PS500. They cover all the important pressure ranges in the machine engineering sector from minus one to zero bar and from zero bar to 400 bar. The pressure can be programmed and displayed either in bar, psi, kPa or Mpa. The sensors are equipped either with two transistor switching outputs or with a switch and an analogue output.
The switch-point accuracy of the device represents 0.5% of the end value. If a sensor is employed at only up to a half of its nominal pressure then it operates, relative to the range used, with an accuracy of 1%, as demanded within the machine engineering sector. As a result it is possible to significantly reduce the number of variants. A further special feature of the sensors: a patent medium stop system seals the sensor in the event of damage to the measuring cell due to overpressure and thus reliably prevents a leak in the machine. With a circumference of just 34 millimetres the sensors can be easily assembled within the common machine engineering grid dimensions of 40 millimetres (middle-middle). The display inclined at 45 degrees enables the sensor to be mounted either at the top or the front of the pressure bearing vessel...
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Endereço |
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TURCK BRASIL -
Sensor do Brasil
Rua Jordão Schiavetto, 436 Hortolândia / SP - Brasil / CEP 13184-080 Tel. : (00 55) 19 3897-9400 Fax. : (00 55) 19 3897-9416 Email: turck@turck.com.br |
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