As we see it, position sensors are usually specified and purchased by machine designers who have two overriding concerns with the parts they specify and use in their product. First, will it meet or exceed the specifications necessary to enable your machine to function the way you intend it to. And second, will it continue to operate properly to avoid nasty and expensive down-time and part replacement for your customers.
What types of things could lead to a position sensor causing unexpected spurious errors or failure that perhaps were unforeseen? Things like magnetic interference from nearby machines, metal flakes or filings common in many manufacturing environments, sufficient speed, shock and vibration either short term or long-term. Long-term meaning a catastrophic failure that only occurs after a time of subjection to repetitive shock and/or vibrations. Let’s look at the potential pitfalls and see how Novopad™ advanced inductive technology enables you to avoid them.
Are your sensors impervious to strong magnetic fields or sensing an incorrect value that has been distorted by an application environment’s magnetic field? Why not prove it to yourself? Take a reasonably strong magnet and run it in the air over your powered and connected magnetostrictive sensor while displaying the values on a display and it’s magnetostrictive position marker resting midway along the sensor. See the value’s change? Not good.
Now, try the same test with the same magnet using the TF1. If configured and connected properly, no significant change will occur.
Your Sensors’s Wear-Free But Is It Flake-Free?
Ready for prove-it-to-yourself test #2? Take some magnetized metal flakes— the kind that are found in many manufacturing sites. Sprinkle some of the flakes over a magnetostrictive sensor near the marker. Now move the marker a few times over the flakes. Notice a resistance to marker motion? Look at the bottom of the marker and imagine the build up of flakes over time. Now you have insight into the real possibility of electromagnetically and mechanically induced errors. With the TF1 Series, the markers are not magnetic and the sensing technology is not magnetic. No magnet to attract the flakes and no magnetic-sensing principle to go awry. Try it.
It’s Only As Fast As The Slowest Part
The cliché time is money is at play in many applications. For example, the faster an injection molding machine can churn out parts, the more profit that piece of capital equipment can make. If your machine is faster, you just gave your customer a better reason to choose your company’s product.
One of the types of parts on many machines including injection molding machines, is the position sensor. It’s update rate is the limiting factor of how quickly sensed positions can be reported as output to a control device. For the TF1 Series this is 100 microseconds—regardless of sensor length or other nebulous factors. Legacy magnetostrictive sensors are typically 10 X or more slower, with the fastest we could find ringing in at 1 millisecond plus other nebulous factors.
Don’t be fooled by competitors who mention a supposedly blazing fast “update rate” of 32 kHz, only to bury the real update rate of sixty-seven milliseconds (67 msec) or even 200 msec or 5 Hz—deep in a specification table!
Machinery that has moving parts has the potential for shock and vibrations to occur. In many machines the vibration level can be significant. The heavier the mass and faster it is moved, the more vibration has to be considered. To avoid having an issue arrive later, Novotechnik designs the TF1 Series as well as all its sensors to the high standard of 100 g shock and 20 g vibration ratings. With competitive products, it’s hit or miss. As a result, Novotechnik‘s customers don’t have vibration issues occurring during prototyping or in the field where their production products are in use.
Name That Spec!
One other factor that is important to know is what the specifications of the products you're considering actually are. With Novotechnik, there’s no guesswork. Product specs are clearly stated and don’t hedge with terms like “depending on dead zones, type of controller attached, null zones, overall sensor length, minimum, if in the optimum range, etc." Neither do you have to find and add up three or four things to find out what the real spec is.
Seeing The Light
TF1 Series consists of an inductively coupled position marker attached to a moving rod/piece of the user’s application that requires a position measurement and the sensor with operational and programming status LEDs. While operating, LEDs indicate whether the sensor is operating and the marker within measuring range, out of range as well as indicating results of internal diagnostics for valid output from the sensor. The LEDs also are used in a programming mode, should your application require custom slope, offset or beginning and end range values.
So, if you need a sensor that’s easy to specify, works right the first time and every time and comes with a dedicated team of technical specialists that highly value providing unmatched customer service... Contact Novotechik.
Novotechnik’s TF1 Series of touchless linear position sensors are based on inductive technology that provides several benefits that can make a big difference to the operation of machinery that are designed into. TF1 Series sensors overcome issues with legacy magnetostrictive technology and enable your application to run much faster than you could with other sensors on the market.
After reviewing the benefits of the TF1 Series, we invite you to read further and look at the test results described below.
TF1 Series Key Specifications:
5) Not Magnetic — Avoid errors from magnetized metal flakes as TF1 Series’ technology does not incorporate a magnet in the moving position marker that can trap flakes between the marker and sensor.
4) EMI Immunity — our advanced inductive sensing is inherently immune to errors from electro-magnetic interference (EMI) generated by high-powered machinery.
3) Speed — with an update rate of 100 microseconds, it is much faster than any magnetostrictive that is currently on the market, and it maintains its full accuracy up to its 10 kHz cycle rate.
2) Robust — TF1 Series of sensors are designed to maintain critical specifications, including absolute linearity of ≤ ±0.025%, even when subjected to shock and/or vibration up to their specified limits of 20 g of vibration and 100 g shock. Many magnetostrictive sensors do not come close.
1) Machine up time — With reproducibility of 10 μm or better for stroke lengths of 400 mm or less and 20 μm or better for stroke lengths >400 μm, combined with the four other key features/specs above, the result is you get better reliability and consistency that holds up in the real world. As a result your machine can deliver more predictable and precise operation as well as uptime to your customers. Advantages like these can give your product an edge over competitors.
Plug-in compatible with most every magnetostrictive sensor.
Please click the PDF icon below to download complete specifications.