The Positek P101 Linear Position Sensor What Can it Do?

Linear position sensors can be used in a variety of applications. Today we take a look at the P101 non contact position sensor.

P101 Linear Position Sensors - What Can They Do?

The Positek P101 is a linear inductive position sensor that can measure a range from 5 to 50mm and is made from stainless steel, able to withstand temperatures from -40°c to 125°c, more than enough for most applications. It is 35mm in diameter and is a standalone sealed unit. In the standard form this is a reliable and adaptable sensor, able to operate in tough conditions without compromising on quality of performance.

The P101 has been at the heart of some interesting custom-built projects, one in particular that involved a lot of refinement and co-operation with the client was installing this sensor at a paper mill, at the request of the machinery manufacturer. Paper factories are vast, with machinery up to 300m long used to press and roll the paper to different finishes. Pulp is fed onto a tape which holds the pulp in a sheet, until it has dried out enough to be handled on its own. This drying process involves high temperatures, as well as humidity, reaching up to 110° in the enclosed area where the sensor system is used. The tape carrying the drying pulp must remain in the right position throughout the process; if it slips or moves then a lot of wastage is produced, as well as causing delays, while the machine is stopped and the tape replaced. The machine can run for 24 hours a day, producing tonnes of paper every year, so stoppages are to be avoided if productivity levels are to be maintained at a reasonable level.

Optical sensors had been used to determine the position of the tape at the end of the drying process, but the market options were limited in terms of durability and reliability, leading the machine manufacturer to seek an improvement to the sensors they had been using. By improving the performance of the machines, they could increase sales by beating the competition on equipment reliability and Positek helped develop a system that would solve one of the main problems that had plagued the industry for years.

The original P101 had most of the features that the client was looking for, but some parts of the equipment had to be adapted to cope with the high humidity. To address this problem, the entire unit was fabricated in stainless steel to solve the potential issue of rusting and corrosion in the warm and wet environment of a paper mill, and the output wiring had to be changed to cope with the constant operation of the sensor. This was originally the main issue for the machinery manufacturer, and turned out to be the one potential issue that was addressed early on and without too much refinement. As the system was tested and other issues uncovered; Positek developed ways to adapt the sensor to address these specific problems, and the result was well received by all involved.

The sensor itself is installed internally in the paper making machine, and requires very little additional set up once the machinery is in place in a factory, as there are only two output connections. The sensor can measure to within ±0.25% of the range required and is reliably accurate in delivering this information. Thanks to these improvements in linear position sensors within paper making machines, productivity can be maintained or even increased, and the incidence of stoppages and waste is decreased, leading to overall greater profitability.