UHF making a big impact on manufacturing

RFIDUltra-High Frequency (UHF) RFID is quickly becoming the go-to identification system for flexible manufacturing lines around the world. While it was once considered to be a system designed primarily for distribution centers and retail stores, UHF technology has evolved to meet the rigors of the manufacturing environment.

Not long ago I was in a discussion with one of my customers who had been using RFID for almost 25 years. He was caught in a tough spot because he had an application which required reading tags from as little as six inches away to as far as two feet away. The HF system he had could easily meet his needs for the six inch read range, but reading at two feet away limited him to using UHF. When I explained that, his bewildered look indicated to me he was reluctant to consider UHF as a real option. He went on to explain that about ten years prior he conducted tests in his plant with UHF and found a host of limitations with the technology. His main concern was how the operators’ two-way radios interfered with the UHF operating frequency of 902-928MHz. Having heard this from other manufacturing organizations who were early adopters I knew right away that he wasn’t aware of how the technology has evolved over the last decade.

Frequency hopping has pretty much eliminated interference with other radio signals. In addition to overcoming radio interference, being able to read and write to tags which are mounted on or near metal and liquids has become a reality with recent advancements. These improvements have led to more flexible read ranges which are a requirement in today’s flexible manufacturing applications.

In a nutshell, the demands of flexible manufacturing have spurred advancements in the process as well as the supporting technology. As it applies to identification of parts or pallets in the manufacturing process, the flexibility of UHF RFID enables manufacturers to gain visibility in their process and provides actionable data that is used to make complex business decisions.

You can learn more about the technology in Balluff’s white paper, What Makes RFID Systems Industrial Strength? or by visiting our website at www.balluff.us/rfid

Posted in All posts, Industrial Identification, Industrial RFID Systems | Tagged , , , , , , , , , , | Leave a comment

External Linear Position Sensors: Floating or Captive Magnet?

External Linear Position Sensors:  Floating or Captive Magnet? 
PFMagnetsLinear position sensors that are designed to be mounted externally on a machine (as opposed to those designed to be installed into a hydraulic or pneumatic cylinder) are available in a variety of form factors that suit a variety of different applications and application requirements.  One of the most common form factors, particularly for magnetostrictive linear position sensors, is a rectilinear aluminum extrusion that houses the sensing element, or waveguide, and the processing electronics.  Commonly, you’ll hear these referred to as profile-style linear position sensors.

CaptiveVSFloating

Captive magnet (left) and floating magnet (right)

With these types of sensors, the moving part of the machine to be measured or monitored is attached to a position magnet.  The position magnet can be either captive or floating (see image to the right).  Each of these magnet configurations offer some inherent advantages.  We’re going to take a closer look at each.

Captive Magnet

A captive magnet glides along in a track that is an integral part of the extruded aluminum sensor housing.  The magnet is attached to the moving part of the machine via a mechanical linkage.  Advantages of a captive magnet arrangement include:

  • Mechanical flexibility: The magnet usually incorporates an articulating swivel or ball joint that is attached via a linking rod to the moving machine part.  That means the sensor doesn’t need to be perfectly in line with the axis of movement.
  • Protection from damage – In some cases, it is necessary to move the sensor out of harm’s way (e.g., extreme heat, caustic chemicals, strong electromagnetic fields, etc.). The linkage can be as long as necessary in order to connect to the sensor, which will be located in a more hospitable environment.

Some things to consider when choosing to use a captive magnet configuration:

  • Binding of the magnet: A high-quality magnetostrictive sensor is going have a near-zero drag coefficient between magnet and extrusion.  The magnet should not bind or drag.  But in some applications, dirt, grease and particulates can accumulate and cause issues.  For these applications, a floating magnet may be a better choice.
  • Mechanical overtravel:  In a captive magnet arrangement, if the machine travel exceeds the physical length of the sensor, the magnet will (of course) fall off the track.  If this is a concern, consider a floating magnet instead.

Floating Magnet

In a floating magnet arrangement, the sensor is located adjacent to the moving machine part.  The magnet is attached to that machine part, usually on a rigid arm or bracket.  Advantages of a floating magnet include:

  • No mechanical contact: The magnet never makes contact with the housing.  This could be important in applications where dirt, grease or particulates tend to collect on the sensor (see photo below)
    harshenvironment
  • Machine overtravel: Since the magnet is completely uncoupled from the sensor, machine overtravel isn’t a problem.  Obviously, if the magnet leaves the sensor, position feedback is lost, but the sensor will resume normal operation once the magnet re-enters the sensor’s range.

Some things to consider when choosing a floating magnet configuration:

Magnet-to-sensor gap:  In some cases the movement of the machine does not allow a consistent magnet-to-sensor gap to be maintained.  In some sensors, this can lead to inconsistent or erratic sensor operation.  Fortunately, there are sensors available with innovative technology that automatically compensates for such gap fluctuations and maintain full performance and specifications even as the gap varies.  Click below to see such technology in action.

Ultimately, the choice between a floating magnet and a captive magnet arrangement is going to be driven by the requirements of your particular application.

Click the link for more information on external-mount linear position sensors.

Posted in All posts, Linear Position and Distance Measurement | Tagged , , , , , , , , | 1 Comment

The basics of IP69K Washdown explained

Ask 10 engineers working in Food & Beverage manufacturing what “washdown” means to them and you will probably get about 12 answers.  Ask them why they wash down equipment and a more consistent answer appears, everyone is concerned about making clean healthy food and they want to reduce areas of harborage for bacteria.  These environments tend to be cool & wet which usually leads the engineers to ask for 316L stainless steel & ingress protection of IP69K from component manufacturers and also ask for special component ratings.

So what are the basic elements of the washdown procedure?

  • Hot! – Minimum 140F to kill microbes & bacteria.
  • High Pressure! – Up to 1000psi to blast away soiled material.
  • Nasty! – Water, caustics, acid detergents, spray & foam everywhere.
  • Hard Work! – Typically includes a hand cleaning or scrubbing of key components.
  • Regular! – Typically 15-20hrs per week are spent cleaning equipment but in dairy & meat it can be more.

What requirements are put onto components exposed to washdown?

  • Stainless Steel resists corrosion and is polished to level the microscopic roughness that provides harborage for bacteria.
  • Special Component Ratings:
    • ECOLAB chemical testing for housings
    • FDA approved materials
    • 3A USA hygienic for US Equipment
    • EHEDG hygienic for European Equipment
  • IP69K is tested to be protected from high pressure steam cleaning per DIN40050 part 9; this is not guaranteed to be immersion rated (IP67) unless specifically identified.

If you are interested in what sensors, networking & RFID products are available for use in food and beverage manufacturing with a washdown environment, please visit www.balluff.us.

 

Posted in All posts | Tagged , , , , , , | Leave a comment

Reed Switches vs. Magnetoresistive Sensors (GMR)

In a previous post we took a look at magnetic field sensors vs inductive proximity sensors for robot grippers. In this post I am going to dive a little deeper into magnetic field sensors and compare two technologies: reed switches, and magnetoresistive sensors (GMR).

Reed Switches

PrintThe simplest magnetic field sensor is the reed switch. This device consists of two flattened ferromagnetic nickel and iron reed elements, enclosed in a hermetically sealed glass tube. As an axially aligned magnet approaches, the reed elements attract the magnetic flux lines and draw together by magnetic force, thus completing an electrical circuit.

While there are a few advantages of this technology like low cost and high noise immunity, those can be outweighed by the numerous disadvantages. These switches can be slow, are prone to failure, and are sensitive to vibration. Additionally, they react only to axially magnetized magnets and require high magnet strength.

Magnetoresistive Sensors (GMR)

PrintThe latest magnetic field sensing technology is called giant magnetoresistive (GMR). Compared to Reed Switches GMR sensors have a more robust reaction to the presence of a magnetic field due to their high sensitivity, less physical chip material is required to construct a practical GMR magnetic field sensor, so GMR sensors can be packaged in much smaller housings for applications such as short stroke cylinders.

GMR sensors have quite a few advantages over reed switches. GMR sensors react to both axially and radially magnetized magnets and also require low magnetic strength. Along with their smaller physical size, these sensors also have superior noise immunity, are vibration resistant. GMR sensors also offer protection against overload, reverse polarity, and short circuiting.

You can learn more about this topic and many others by visiting www.balluff.us/basics.

Posted in Inductive Proximity Sensors, Magnetic Field Sensors, Object Detection Sensors | Tagged , , , , , , , , , | 1 Comment

Is IO-Link only for Simplifying Sensor Integration?

PossibilitiesOn several occasions, I was asked what other applications IO-Link is suitable for? Is it only for sensor integration? Well the answer is no! There are several uses for IO-Link and we are just beginning to scratch the surface for what IO-Link can do. In this blog post I will cover at least 7 common uses for IO-Link including sensor integration.
IO-Link in essence provides tremendous flexibility. Each available IO-Link port offers the possibility to connect devices from hundreds of manufacturers to build a resilient distributed modular controls architecture — that is essentially independent of the fieldbus or network. IO-Link is the first standardized sensor/actuator communication protocol as defined in IEC61131-9.

USE-CASE #1: Simplify sensor integration
Multitudes of IO-Link sensors from 100+ manufacturers can be connected using the simple 3-wire M12 prox cables. No shielded cables are required. Additionally, using IO-Link provides a parameterization feature and anti-tampering abilities- on the same 3 wires. The sensor can be configured remotely through a PLC or the controller and all the configuration settings can be stored for re-application when the sensor is replaced. This way, on your dreaded night shift changing complex sensor is just plug-n-play. Recipe changes on the line are a breeze too. For example, if you have an IO-Link color sensor configured to detect a green color and for the next batch you want to start detecting red color- with IO-Link it is simply a matter of sending a parameter for the color sensor – instead of sending a maintenance person to change the settings on the sensor itself — saving valuable time on the line.
color sensors

USE-CASE #2: Simplify analog sensor connections
In one of my previous blogs, “Simplify your existing analog sensor connection”, I detailed how connecting an analog sensor with single or multi-channel analog-to-IO-Link (A/D) converters can eliminate expensive shielded cables and expensive analog cards in the controller rack and avoids all the hassle that comes with the analog sensors.

USE-CASE #3: Simplify RFID communication
IO-Link makes applications with RFID particularly intriguing because it takes all the complexity of the RFID systems out for simple applications such as access control, error-proofing, number plate tracking and so on. In an open port on IO-Link master device you can add read/write or read only RFID heads and start programming. A couple of things to note here is this IO-Link based RFID is geared for small data communication where the data is about 100-200 bytes. Of-course if you are getting into high volume data applications a dedicated RFID is preferred. The applications mentioned above are not data intensive and IO-Link RFID is a perfect solution for it.

USE-CASE #4: Simplify Valve Integration
valve manifoldTypically valve banks from major manufacturers come with a D-sub connection with 25 pins. These 25 wires are now required to be routed back to the controls cabinet, cut, stripped, labeled, crimped and then terminated. The other expensive option is to use a network node on the valve bank itself, which requires routing expensive network cable and power cable to the valve bank. Not to mention the added cost for the network node on the valve bank. Several manufacturers now offer IO-Link on the valve manifold itself simplifying connection to 4-wires and utilizing inexpensive M12 prox cables. If you still have the old D-sub connector, an IO-Link to 25-pin D-sub connectors may be a better solution to simplify the valve bank installation. This way, you can easily retrofit your valve bank to get the enhanced diagnostics with IO-Link without much cost. Using IO-Link valve connectors not only saves time on integration by avoiding the labor associated with wire routing, but it also offers a cost effective solution compared to a network node on the valve manifold. Now you can get multiple valve manifolds on the single network node (used by the IO-Link master) rather than providing a single node for each valve manifold in use.

USE-CASE #5 Simplify Process Visualization
Who would have thought IO-Link can add intelligence to a stack light or status indicator? Well, we did. Balluff introduced an IO-Link based fully programmable LED tower light system to disrupt the status indicator market. The LED tower light, or SmartLight, uses a 3-wire M12 prox cable and offers different modes of operations such as standard stack light mode with up to 5 segments of various color lights to show the status of the system, or as a run-light mode to display particular information about your process such as system is running but soon needs a mechanical or electrical maintenance and this is done by simply changing colors of a running segment or the background segment. Another mode of operation could be a level mode where you can show the progress of process or show the fork-lift operators that the station is running low on parts. Since the Smartlight uses LEDs to show the information, the colors, and the intensity of the light can be programmed. If that is not enough you can also add a buzzer that offers programmable chopped, beep or continuous sound. The Smartlight takes all of the complexity of the stack light and adds more features and functions to upgrade your plant floor.

USE-CASE #6: Non-contact connection of power and data exchange
Several times on assembly lines, a question is how to provide power to the moving pallets to energize the sensors and I/O required for the operation? When multi-pin connectors are used the biggest problem is that the pins break by constantly connecting or disconnecting. Utilizing an inductive coupling device that can enable transfer of power and IO-Link data across an air-gap simplifies the installation and eliminates the unplanned down-time. With IO-Link inductive couplers, up to 32 bytes of data and power can be transferred. Yes you can activate valves over the inductive couplers!  More on inductive coupling can be found on my other series of blogs “Simple Concepts for Complex Automation”

USE-CASE #7: Build flexible high density I/O architectures.
IO PointsHow many I/O points are you hosting today on a single network drop? The typical answer is 16 I/O points. What happens when you need one additional I/O point or the end-user demands 20% additional I/O points on the machine? Until now, you were adding more network or fieldbus nodes and maintaining them. With I/O hubs powered by IO-link on that same M12 4-wire cable, now each network node can host up to 480 I/O points if you use 16 port IO-Link masters. Typically most of our customers use 8-port IO-Link masters and they have the capacity to build up to 240 configurable I/O on a single network drop. Each port on the I/O hub hosts two channels of I/O points with each channel configurable as input or output, as normally open or normally closed. Additionally, you can get diagnostics down to each port about over-current or short-circuit. And the good thing is, each I/O hub can be about 20m away.

In a nutshell, IO-Link can be used for more than just simplifying sensor integration and can help significantly reduce your costs for building flexible resilient controls architectures. Still don’t believe it? Contact us and we can work through your particular architecture to see if IO-Link offers a viable option for you on your next project.

Learn more about our IO-Link solutions at www.balluff.com/io-link

Posted in All posts, Industrial Networking, IO-Link | Tagged , , , , , , , , , , , , , | 1 Comment

Quick field replacement for linear sensor electronics

Micropulse Transducers BTL 7 Rod-style with Rapid Replacement Module

Micropulse Transducers BTL 7
Rod-style with Rapid Replacement Module

When maintenance technicians replace linear position sensors (also known as probes or wands) from hydraulic cylinders, it can leave a terrible mess, waste hydraulic oils, and expose the individual to harmful hot fluids.  Also, the change out process can expose the hydraulic system to unwanted contaminants. After the sensor replacement has been completed, there can also be more work yet to do during the outage such as replacing fluids and air-bleeding cylinders.

Hydraulic linear position sensors with field-replaceable electronics/sensing elements eliminate these concerns.  Such sensors, so-called Rapid Replacement Module (RRM) sensors, allow the “guts” of the sensor to be replaced, while the stainless steel pressure tube remains in the cylinder.  The hydraulic seal is never compromised.  That means that during the replacement process there is no danger of oil spillage and no need for environmental containment procedures. There is also no need to bleed air from the hydraulic system and no danger of dirt or wood debris entering the open hydraulic port. Finally, there is no danger of repair personnel getting burned by hot oil.

The RRM is an option for Balluff’s BTL7 Z/B Rod Series used in applications for the lumber industry, plastic injection and blow molding, tire and rubber manufacturing, stamping presses, die casting, and all types of automated machinery where a continuous, absolute position signal is required.  Applications in industries such as Oil & Gas and Process Control are especially critical when it comes to downtime.  For these applications, this Rapid Replacement Module capability is especially advantageous.

You can learn more about linear position sensors with hazardous area approvals, by visting http://www.balluff.com/balluff/MUS/en/products/explosion-proof-hazardous-position-sensor-btl7.jsp

The video below shows a demonstration of the Rapid Replacement Module in action.

For more information on this topic, please visit www.balluff.com/balluff/MUS/en/news/micropulse-generation7-with-rapid-replacement-module.jsp

Posted in All posts, Linear Position and Distance Measurement | Tagged , , , , , , , , , , , , , , , , , | 1 Comment

Basic Sensors for Robot Grippers

Robot gripper with inductive proximity sensors mounted

Robot gripper with inductive proximity sensors mounted

Typically when we talk about end-of-arm tooling we are discussing how to make robot grippers smarter and more efficient. We addressed this topic in a previous blog post, 5 Tips on Making End-of-Arm Tooling Smarter. In this post, though, we are going to get back to the basics and talk about two options for robot grippers: magnetic field sensors, and inductive proximity sensors.

One of the basic differences is that detection method that each solution utilizes. Magnetic field sensors use an indirect method by monitoring the mechanism that moves the jaws, not the jaws themselves. Magnetic field sensors sense magnets internally mounted on the gripper mechanism to indicate the open or closed position. On the other hand, inductive proximity sensors use a direct method that monitors the jaws by detecting targets placed directly in the jaws. Proximity sensors sense tabs on moving the gripper jaw mechanism to indicate a fully open or closed position.

BMF_Grippers

Robot gripper with magnetic field sensors mounted

Additionally, each solution offers its own advantages and disadvantages. Magnetic field sensors, for example, install directly into extruded slots on the outside of the cylinder, can detect an extremely short piston stroke, and offer wear-free position detection. On the other side of the coin, the disadvantages of magnetic field sensors for this application are the necessity of a magnet to be installed in the piston which also requires that the cylinder walls not be magnetic. Inductive proximity sensors allow the cylinder to be made of any material and do not require magnets to be installed. However, proximity sensors do require more installation space, longer setup time, and have other variables to consider.

For more information in this topic and others visit www.balluff.us/basics.

Posted in All posts, Inductive Proximity Sensors, Magnetic Field Sensors, Object Detection Sensors | Tagged , , , , , , , , , , , , , , , | 2 Comments

The promise of the Industrial Internet of Things (IIoT)

Things to Avoid and Pursue

There is a long list of activities Control Engineers and Plant Managers avoid like the plague…

  • Modifying PLC code
  • Adding an HMI
  • Modifying HMI screens
  • Adding additional Indicators

On the other side, there is a list of activities they need to do to keep their plant on the forefront of lean manufacturing…

  • Providing real-time operational visibility
  • Adding new manufacturing/process functions
  • Adding/updating Error Proofing devices
  • Providing preventative and predictive maintenance information
Scaling up to IIoT with IO-Link and Balluff's Virtual IP Address Concept

Scaling up to IIoT with IO-Link and Balluff’s Virtual IP Address Concept

Fortunately, the IIoT can help you avoid what you want to avoid and do more of what you need to do. The promise of IIoT can be realized with an IO-Link Architecture featuring Balluff’s Virtual IP address concept. This scalable architecture allows the PLC to do its thing while an independent PC (the one on your desk for example) can access the IO devices directly to get at operational and process data not always available in the PLC.

Learn more at www.balluff.us/io-link.

Posted in All posts, Industrial Networking, IO-Link | Tagged , , , , | 1 Comment

Photoelectric Basics – Distance Measuring

Some photoelectric applications require not only knowing if the object is present or not but exactly where the object is while providing a continuous or dynamic value representative of the objects location.  For instance, if a robot is stacking a product is the stack at the correct height or how many additional pieces can be placed on the stack, how large is the coil or roll diameter of a product, and how high is the level or how much further can the product move before it is in position.  Distance sensors can provide this dynamic information and in some case provide a digital output as well for alarms.

RetroreflectiveThese sensors are normally based on diffuse sensing technology. However, in some cases retro-reflective technology is used for extremely long sensing distances.  As with diffuse sensors there is only one device to mount and wire.  However, due to the technology required for the higher resolutions, lensing, electronics and outputs these devices are typically much more expensive than a discrete diffuse sensor.

Similar to a diffuse sensor the distance sensor emits a pulsed light that strikes an object and a certain amount of light is reflected back to the sensor’s receiver.  The sensor then generates an analog output signal that is proportional to the distance to the target.  The technology that is utilized within the sensor to determine the distance is either Time of Flight or Triangulation.

PrintTime of Flight sensors are more immune to target color and texture than light intensity based system because of the time component.  These devices measure greater distances than the triangulation method however there is a sacrifice in resolution.

PrintTriangulation sensors emit a pulsed light towards the target object.  The light is then reflected back to the receiver.  When the light reaches the sensor it will strike the photosensing diode at some angle.  The distance between the sensor and the target determines the angle in which the light strikes the receiver.  The closer the target is the sensor the greater the angle.
Triangulation based sensors being dependent on the amount of reflected light are more susceptible to target characteristics such as color and texture.  These sensors are characterized by short to mid-range sensing distance however they provide higher resolutions than TOF sensors.

Output signals are either 0…10 volts, 1…10 volts or 4…20mA each of which has their pros and cons.  Voltage outputs, 0 – 10 or 1- 10 volts, are easier to test and there is typically a broader offering of interface devices.  However voltage outputs are more susceptible to noise from motors, solenoids or other coils and voltage drops of the wire.  In addition generally voltage output cable runs should be less than 50 feet.  Also since 0 volts is an acceptable output value broken wires, device failures, or power failures can go undetected.

Current outputs, 4 – 20 mA, provide the best noise immunity, are not affected by voltage drop and the cables lengths can exceed 50 feet.  Since the sensor will be providing 4mA at zero distance its lowest possible signal, if the sensor should fail, the cable damaged or a power failure the interface device can detect the absence of the signal and notify an operator.  Current outputs are more difficult to test and in some cases are affected by temperature variations.

For more information about photoelectric sensors, request your copy of Balluff’s Photoelectric Handbook.

Posted in All posts, Object Detection Sensors, Photoelectric Sensors | Tagged , , , , , , , , , , | 1 Comment

Sensor Reliability in Steel Production

01_SteelIn any continuous manufacturing process such as steel production, increased throughput is the path to higher profits through maximum utilization of fixed capital investments. In order to achieve increased throughput, more sophisticated control systems are being deployed. These systems enable ever-higher levels of automation but can present new challenges in terms of managing system reliability. Maintenance of profit margins depends on the line remaining in production with minimal unexpected downtime.

It is essential that control components, such as sensors, be selected in accordance with the rigorous demands of steel industry applications. Standard sensors intended for use in more benign manufacturing environments are often not suitable for the steel industry and may not deliver dependable service life.

When specifying sensors for steel production applications, some environmental conditions to consider include:

Heat

High-temperature M30 proximity sensor.

High-temperature M30 proximity sensor.

High temperatures exist in many areas of the steel-making process, such as the coke oven battery, blast furnace, electric arc furnace, oxygen converter, continuous casting line, and hot rolling line. Electronic components are stressed by elevated temperatures and can fail at much higher rates than they would at room temperature. Heat can affect sensors through conduction (direct transfer from the mounting), convection (circulating hot air), or radiation (line-of-sight infrared heating at a distance). The first strategy is to install sensors in ways that minimize exposure to these three thermal mechanisms. The second line of defense is to select sensors with extended temperature ratings. Many standard sensors can operate up to 185° F (85° C) but high temperature versions can operate to 212° F (100° C) or higher. Extreme temperature sensors can operate to 320° F (160° C) or even 356° F (180° C).

Don’t forget to consider the temperature rating of any quick-disconnect cables that will be used with the sensors. Many standard cable materials will melt or break down quickly at higher temperatures.  Fiberglass-jacketed cables, for example, are rated to 752° F (400° C).

Shock and Vibration

Hydraulic cylinder position sensor rated at 150 G shock.

Hydraulic cylinder position sensor rated at 150 G shock.

Steel making involves large forces and heavy loads that generate substantial amounts of shock under normal and/or abnormal conditions. Vibration is also ever-present from motors, rollers, and moving materials. As with heat, look for sensors with enhanced specifications for shock and vibration. For sensors with fixed mountings, look for shock ratings of at least 30 G. For sensors mounted to equipment that is moving (for example, position sensors on hydraulic cylinders), consider sensors with shock ratings of 100 to 150 G. For vibration, the statement of specifications can vary. For example, it may be stated as a frequency and amplitude, such as 55 Hz @ 1 mm or as acceleration over a frequency range, such as 20 G from 10…2000 Hz.

Don’t forget that the quick-disconnect connector can sometimes be a vulnerability under severe shock. Combat broken connectors with so-called “pigtail” or “inline” connectors that have a flexible cable coming out of the sensor that goes to a quick-disconnect a few inches or feet away.

Mechanical Impact

Steelface proximity sensors bunkered in protective mounting.

Proximity sensor bunkered in a protective mounting block.

The best way to protect sensors from mechanical impact is to install them in protective mounting brackets (a.k.a. “bunker blocks”) or to provide heavy-duty covers over them. When direct contact with the sensor cannot be avoided, choose sensors specifically designed to handle impact.

Another strategy is to use remote sensor actuation to detect objects without making physical contact with the sensor itself.

Corrosion and Liquid Ingress

In areas with water spray and steam, such as the scale cracker on a hot strip line, corrosion and liquid ingress can lead to sensor failure. Look for stainless steel construction (aluminum can corrode) and enhanced ingress protection ratings such as IP68 or IP69K.

When All Else Fails…Rapid Replacement

Quick-change prox mounts for proximity sensors.

Quick-change prox mounts for proximity sensors.

If and when a sensor failure inevitably occurs, choose products and accessories that can minimize the downtime by speeding up the time required for replacement.

Strategies include quick-change sensor mounts, rapid-replacement sensor modules, and redundant sensor outputs.

In the case of redundant sensor outputs, if the primary output fails, the system can continue to operate from the secondary or even tertiary output.

You can learn more about sensing solutions for the Steel Industry in Balluff’s industry brochure.

Posted in All posts, Cables and Connectors, Inductive Proximity Sensors, Linear Position and Distance Measurement, Object Detection Sensors, Sensor Accessories | Tagged , , , , , , , , , , , | 1 Comment