Gas Turbine Monitoring with Kistler Pressure and Acceleration Sensors

AP Corporation is pleased to present Gas Turbine Monitoring with Kistler Pressure and Acceleration Sensors

Kistler high-temperature measuring systems allow measuring thermoacoustics phenomena in harsh environments with extreme temperatures up to 700°C.

• Safe and reliable operation of gas turbines thanks to combustion dynamics monitoring.
• Differential charge amplifier designed for high temperature sensors.
• High temperature acceleration sensors measuring vibrations.
• High temperature pressure sensors measuring pressure pulsations.
• Reliable monitoring with durable sensors in harsh environments and up to 700°C / 1300°F.
• Predict, monitor and analyze combustion dynamics.
• Complete differential, ground insulated measuring chains enable early detection of smallest pressure pulsations.

Features of Kistler measuring equipment for combustion dynamics monitoring:

• Resistant to high temperature (700°C / 1300°F)
• Ex certified and interference resistant (EMI, RF)
• PiezoStar sensing element - not pyroelectric and no popcorn effect

For more information, contact AP Corp. for Kistler products in New England. You can reach them by calling (508) 351-6200 or visit https://a-pcorp.com.

Why Plastics Industry Feed Screws are Designed the Way They Are

Download the white paper here.

The selection of the proper screw for a given injection molding or extrusion application can be critical to its success.

Screw geometry — length-to-diameter ratio, profile, channel depth, compression ratio, helix angle and a host of special design features — has everything to do with how well the screw performs in a given application.

There are documented applications where customers have improved production rates or reduced cycle times by 30 or 40% simply by switching to an improved screw design. Similarly, reject rates have been lowered from more than 4-6% to less than 1% by incorporating a custom designed mixing screw.

And experience shows that the amount of color concentrate required to achieve optimum color mix can be typically reduced from 4% (of the total blend) to 2%, just by using an optimized screw design. When considering resin and concentrate costs, payback for an optimized screw and non-return valve design can be almost immediate.

This white paper, published by Glycon Corporation, provides an in-depth look into plastics industry feed screw design.

DOWNLOAD THE WHITE PAPER FROM THIS AP CORP WEB PAGE

In-Line Color Measurement for Recycled Plastic

Photo 1 - Recycled Plastic with Color

INTRODUCTION 

Color measurement is a well-accepted technology to check the quality of the color values in the production process. Usually these measurements are performed "off-line".

The delay between sampling and obtaining the results from the laboratory can be time consuming. A significant disadvantage is that only a single measurement is generated in this time period and the quality of the color during, before and after the sampling point is unknown.

With the in-line color measurements taking place directly in the melt, not only is complete documentation possible, but when color variations occur, immediate intervention can take place.

Photo 2 - Reflection probe in strand pelletizer.

When recycling plastic to convert to new uniform  colored pellets many challenges can take place. Recycled plastic is much more inconsistent than virgin material. Understand-ing this inconsistency will help on your color dosing to provide a more homogeneous final product. With the proper color measurement system you can know the color values of your extrudate in real time. This allows for closing the loop on your color by changing your dosing rates to meet your specifications.

INNOVATIVE NEW TECHNOLOGY

Photo 4 - Stainless Steel NEMA4 box with touch-screen.

Technology from Equitech, a manufacturer of in-line process instrumentation, deploys a probe directly in the molten polymer. Their Reflection Polymer Melt Probe (RPMP, Photo 2) is installed on the exit (adapter) of the extruder by using ½”-20 UNF thread (typically Dynisco®). The RPMP is screwed into position in the adapter between the extruder and the die. The RPMP consists of the threaded body and optical fibers. The sapphire lens on the tip of the probe is the observation window and is very well suited to the harsh conditions in the extruder (temperature, pressure, and friction through flowing material). The self-cleaning function of the sapphire is ensured by the shear force of the material flow. Ideal installation is directly into the melt stream in the adapter.

Off-line measurements are used more effectively by downloading them to the Equitech Inline Color Spectrophotometer. This can be done manually or through OPC communications. By having the laboratory target values displayed on the Equitech system the operator can view trends of L*, a*, b* and Delta E.

This method provides complete documentation of a particular extrusion run. It also matches the known laboratory measurements giving confidence that an extrusion run has maintained specifications throughout its entirety. When color variations occur, notification can take place via digital alarms. Intervention can take place via OPC or analog signals i.e. L* feedback for closed loop color control.

Photo 3 - Trend charts of EquiColor Software

COLOR MEASUREMENT 

Illumination of the polymer through the sapphire window is achieved by 6 circumferentially-positioned glass fibers which convey the light of a xenon flash lamp. The reflection from the illuminated surface is detected by one center-positioned optical fiber. This reflected light is then interpreted by the spectrophotometer. Color values such as L*, a*, b* C*, h are calculated from this spectral curve, and displayed as trend charts, (see Photo 3).

For a continuous process monitoring, 10 to 60 seconds is recommended as the measurement interval. Intervals as fast as 1 to 2 seconds are possible. The calibration of the spectrophotometer is designed specifically for the demands of the production process. Calibration can be done without interruption of the process.

USER BENEFITS

• Real-time information about process stability & quality
• Impact of speed changes on the quality of the extrusion
• Controlled color changes: start phase, end of run  
• Avoid off-specification batches & waste production
• Detection of dosage elevations
• Optimized recipe formulation & process design
• Available feedback loop for L* closed loop control via feeder
• Comprehensive quality audit trail customer documentation

For more information, contact AP Corp. by calling (508) 351-6200 or visiting https://a-pcorp.com.

Reprinted with permission from Equitech International Corporation.

The Three Most Common Types of Temperature Sensors

Various types and styles of temperature sensors (Pyromation).

This post describes the three most popular temperature sensors, how they function, and where they are used.

THERMOCOUPLES

Thermocouple illustration showing base metal designs
with various types of junctions (Pyromation).

Thermocouples are temperature sensing devices that operate on a phenomena called the Seebeck
effect. In the simplest terms, thermocouples produce a micro-voltage between two conductors - joined at each end and made of dissimilar metals - when one junction varies in temperature and the second junction (called the reference junction) is known and maintained at a constant temperature. The corresponding voltage produced at the sensing junction can be measured and directly correlated to the change in the sensing junction's temperature.

Thermocouples are popular and widely used in industrial and commercial temperate systems because they are:

• Cost-effective.
• Provide good accuracy.
• Have a sufficiently linear temperature-to-signal output curve.
• Are available in many different metal alloys for many different temperature ranges.
• Are easily interchangeable.

Thermocouples require no external power source to work and can be used in continuous temperature measurement applications from -185 Deg. Celsius (Type T) up to 1700 Deg. Celsius (Type B).

Thermocouples are commonly found in many industrial processes. Examples are the plastics industry, primary metals, power generation, kilns, industrial boilers, HVAC, gas turbine exhaust systems and and diesel engines. And because they are affordable and easy to produce, thermocouples are also used in many consumer applications, such as residential and commercial cooking and heating equipment.

RTDs

Wire wound RTD
(Image courtesy Wikipedia)

Resistance Temperature Detectors, referred to as RTD’s, are temperature sensing devices that determine temperature based on a relative change in resistance of the sensing element. The sensing element is a wire or etched circuit made from a metal with a well established resistance to temperature curve, most commonly platinum, nickel, or copper.  Platinum, nickel and copper are used because they produce a predictable and stable change in resistance as the temperature changes. Normally the wire is coiled around a bobbin (made of glass or ceramic), and inserted into a protective sheath. Alternatively, RTD's can also be manufactured as a thin-film, etched element with the pure metal deposited on a ceramic base, very similar to the way a printed circuit is made.

RTD’s are popular because:

• They offer considerably higher accuracy and repeatability than thermocouples.
• Can be used up to 600 Deg. Celsius.



Thin-film RTD
(Image courtesy of Wikipedia)

• Can be integrated directly on the part to be monitored.

They are used where accuracy is important, such as in biomedical applications, semiconductor processing and temperature critical industrial applications. They tend to be higher priced than thermocouples because they are made of pure metals, and they do need an excitation voltage from an external source for the device to be read.

THERMISTORS

Another very common temperature sensing device is the thermistor. Thermistors are also a resistance measuring device similar to RTD’s. However, instead of using a pure metal as the resistance element, thermistors employ a very inexpensive polymer or ceramic resistance element. While these materials are very cost-effective, the downside is the resistance-to-temperature output curve. The change in resistance to a corresponding temperature change is very non-linear, and as such, make thermistors' use practical only within a narrow temperature range.

Thermistors are very inexpensive and have a very fast response making them very attractive in applications where a narrow sensing range exists and cost is important. Thermistors also come in two varieties, PTC, or positive temperature coefficient, and NTC, or  negative temperature coefficient. PTC's resistance increases with increasing temperature,  while NTC's resistance decreases with increasing temperature.

Thermistors are used widely in food processing in digital thermostats, and for on-board temperature monitoring of electronics and circuit boards. They are also used widely in many consumer appliances.

For more information on any temperature sensing application, contact AP Corp and discuss your requirement with one of their experienced application experts. They can be reached at (508) 351-6200 or visit them at https://a-pcorp.com.

Dynisco Online Viscosity Measurement

From the Dynisco presentation "From lab to production, providing a window into the process."

Get maximize extrusion efficiency with Dynisco Online Rheological Testing.

Dynisco online rheometers provide a "window into your process" with the ability to continuously measure critical parameters form melt flow ratio to intrinsic / relative / melt viscosity and from constant shear rate to shear sweep.

The video above introduces the Dynisco ViscoSensor, CMR IV, and FCR and presents the viewer a cost justification for their use. You can also download the presentation from the AP Corp. website here.

For more information in New England and Upstate New York, contact AP Corp. by calling (508) 351-6200 or by visiting https://a-pcorp.com.

What are Plastics Industry Feed Screws and How Are They Made?

Feed screw maintenance.

Plastics industry feed screws, or feed screw augers, are mechanisms that use rotating helical screw blades to move plastics pellets through the barrel of molding and extrusion equipment. The feed screw transports the plastic as it changes phase from solid to viscous liquid through friction, shear, and conductive heat transfer. 

A typical feed screw has three zones. Plastic pellets enters the screw feed section where the pellets are compacted and conveyed. Next is the transition (or compression) section, where the plastic is compressed, conveyed, and melted.  Finally, the liquid plastic moves to the metering section where it is precisely controlled at optimum temperature and viscosity.

For more information about feed screws, or any part of the injection molding process, contact:

AP Corp.

https://a-pcorp.com

508-351-6200

Diagram of injection molding process.

Strain Gage Sensors with Pre-attached Lead Wires

The following is from the podcast "StrainBlog" (https://www.strainblog.com) about exciting new technology for adding lead wires to strain gages. The discussion between hosts Jim and Darryl is about the development and virtues of the new Advanced Sensors Technology C4A and C5K strain gages.

AP Corp.
508-351-6200

https://a-pcorp.com

For Strain Gage Users Who Hate to Solder - New Strain Gage Sensors with Pre-attached Leads

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The following is the transcript from the podcast "StrainBlog" (https://www.strainblog.com) about exciting new technology for adding lead wires to strain gages. The discussion between hosts Jim and Darryl is about the development and virtues of the new Advanced Sensors Technology C4A and C5K strain gages.

---

Jim - The topic that keeps coming up repetitively is gauges with pre-attached lead wires. I got a myriad of customers looking for a variety of different solutions. Everything from printed circuit boards, where we've got to route very fine lead wires from gauges to data acquisition systems;  civil engineering projects where they're looking for low cost, long cable lengths, sometimes two wires, sometimes three wire. There seem to be more and more demands - what are we doing to meet this variety of applications that we sort of lump into this category of pre-leaded strain gages?

Darryl - Jim, that's a fantastic question. So, we've got this new line of strain gages we call C4A's [from Micro-Measurements], and they they're available in a bunch of different sizes. We go down right now to about a 0.062" gage length, and we go up to a 0.235" gage length. We put a two conductor and a three conductor wire on it on. We can vary the length of that, and these gages are actually made using our new technology from the Advanced Sensors Group, where we can really push the limits now both on the size of the strain gage as well as the resistance. We're really excited about these. We're targeting different markets, including structural testing, as well as printed circuit board testing. There's also another one that we've recently introduced, which is a C5K version, and that's a three element rosette, a planar style that's in a 350 Ohm resistance, and with this new technology, we can make this gauge smaller, more compact than ever before, and it really makes it ideal for printed circuit board testing, where you're trying to get up close to the components that's on that board, so that you could get very accurate, localized strain gage measurements.

Jim - Now, I think I've seen one of the C5K gages that you refer to, and that's a remarkably small planar gage. If I'm correct, the footprint of that planar gage is even smaller than the smallest stacked rosette that we've ever made. Is that true?

Darryl - Yeah, you're absolutely right. So, one of the smallest stacked rosettes we've had is the 031WW as well as the G1350, and this new planar gage will actually fit within the footprint of both of those gages. The active gauge length is less than 0.020 of an inch, and we also pre-attach three conductor, 36 gauge wire to each one of those grids, so basically, you have a planar rosette with 10 feet of three conductor Teflon insulated wire that's 36 gauge in size.

Jim - Well that seems to solve a lot of problems. With stacked rosette that you have a lot of self heating issues, trying to dissipate the heat from those three layers, down to a single plane and dissipate that. With the planar rosette, all gauges air on the single plane - you don't have a proximity issue with height of sight from the neutral axis,  you don't have that heat build up, and if I remember correctly, these are actually 350 Ohm gages, not 120.

Darryl - That's absolutely right. You hit the nail on the head. These are 350 Ohm gages, so you don't have to be as concerned about self heating effects, because of the higher resistance, and also because it's a planar, and like you mentioned, there's not as much of a superposition error because that's a planar gage and not a stack one. So there should be less correction due to bending and also less concern related to excitation and self-heating of the strain gage. We're really excited about adding this to our portfolio of strain gauges that customers can use now to do this printed circuit board type testing.

Jim - And that coupled with the fine wires solves a wire routing issue, getting those leads out from between components out of the package to the data acquisition system. Sounds like a perfect solution to me.

Darryl - Yeah, we're really excited about.

For more information on strain gage sensors with pre-attached leads in New England or Upstate New York, contact AP Corp. by calling (508) 351-6200 or visit their website at https://a-pcorp.com.

White Paper: Learn Why Eddy-Current Sensors Are Now Replacing Inductive Sensors and Switches

Recent advances in eddy-current sensor design, integration and packaging, as well as overall cost reduction, have made these sensors a much more attractive option than inductive sensors. This is especially true where high linearity, high-speed measurements and high resolution are critical requirements.

This white paper, courtesy of Micro Epsilon and AP Corp, explains why.

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DOWNLOAD THE WHITE PAPER FROM THE

AP CORP WEB SITE HERE

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AP Corp

https://a-pcorp.com

(508) 351-6200

An Introduction to Sentek Dynamics Vibration Testing Systems

Download the full paper here.

Whether you are shopping for your first shaker system, or just educating yourself on vibration and shaker technology in general, you'll find this white paper on Sentek Dynamics shakers helpful. Sentek Dynamics supplies vibration test equipment to reproduce real-world environmental conditions for global manufacturers and offers technology capable of reproducing a wide-variety of test requirements - vibration (sine, random, shock, SoR, RoR, RSTD and others), data recording and dynamic signal analysis.

Although this paper focusses on Sentek Dynamics products, it provides excellent details about shaker technology in general.

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Get the full Sentek Dynamics Vibration Testing Systems Introduction paper at this AP Corp. web page.

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Check Out the Current AP Corp. Line Sheet

AP Corp. represents the top manufactures of industrial sensors and instrumentation. Product categories include Analyzers, Color Sensors, Displacement Sensors, Flow Sensors, Instrumentation (Data Acquisition), Load Cells & Instrument Hardware, Machine Controls, Pressure Gauges, Pressure Sensors, Sanitary Sensors, Sound Sensors, Strain Gages, Temperature Sensors, and Vibration Sensors. As one of New England's and New York's premier Manufacturer's, AP Corp. will assist you in selecting the perfect sensor for your application.

Check out the AP line sheet by reviewing the embedded document below, or you can download a PDF line sheet from this page on the AP Corp. web site.

AP Corp.
https://a-pcorp.com
(508) 351-6200

AP Corp Sensors and Instrument Line Card 2019 from AP Corp. - Sensors and Instrumentation

Dynisco ViscoSensor for Online Rheological Measurement

Dynisco ViscoSensor for the thermoplastics resin industry.

Specifically suited for all “return to process” looking to improve quality of their process and product by ensuring the rheological properties continuously in their production line.

Designed for the thermoplastics resin market, the Dynisco ViscoSensor provides the continuous measurement of melt flow rate, or apparent or intrinsic viscosity, directly on the manufacturing process.

To learn more about online rheological measurement with the Dynisco ViscoSensor visit this page on the AP Corp website.

Andruss-Peskin (AP) Corporation
(508) 351-6200
https://a-pcorp.com

Andruss-Peskin Introduction Video

Here's a short introduction video for those of you who don't yet know AP Corp. Thanks for watching.

Welcome to the Sensor and Instrumentation Blog of New England

Thanks for visiting! It's our intention to feature products, technologies, and concepts of interest to the sensor and instrumentation  community. Subjects will include all types of industrial sensors and instrumentation, basics of operation, and new exciting products.

Among the products and applications we will feature are: analyzers, color sensors, displacement sensors, flow sensors, industrial weighing, instrumentation (data acquisition), load cells & instrument hardware. machine controls, pressure gauges, pressure sensors, sanitary sensors, strain gages, and temperature sensors.

We hope you enjoy and visit back frequently!