Precise Mass Flow Enables Novel Pollution Sensing Technologies

Alicat Mass Flow provides accurate control of gasses under test

The growth of the IoT (Internet of Things) is driving the need for smaller and more ubiquitous sensors. Normally, one thinks of optical or electrical sensors in this context. This type of measurement has typically been in the province of automotive and process control industries and is largely unavailable at the consumer level. Presently, IoT is creating a need for low-power, low-cost gas sensors that can be utilized for consumer level applications. There are potential applications in the area of household air-quality monitoring, personalized healthcare, breath analysis and a multitude of other applications. However, existing sensors that could be used for these applications are generally not suitable due to large size, higher power demands and/or high cost. There are a number of competing technologies focused on providing sensors for this market; one of the most promising sensor types is the field-effect transistor (FET). In a recently published paper, Fahad et. al. describe a novel FET that promises to meet many of the requirements where existing sensors fall short. Many of the experiments described in the paper require highly accurate mass flow of measured gases – precisely provided by a set of Alicat mass flow controllers. 1

Fahad et. al. demonstrate a novel chemically-sensitive FET capable of detecting H2S as low as 10ppb. Sulfur Dioxide is an invisible gas that readily forms harmful compounds, including sulfuric acid and sulfate particles. Sulfur dioxide is a toxic air pollutant and is especially dangerous to asthma sufferers. The US, in particular, has made great strides in reducing sulfur emissions from powerplants. However, in excess of 500 million tons were still produced in 2011 from powerplants and other sources. 2 The same series of experiments showed detection of NO2 down to 1ppm levels.  Nitrogen Dioxide is another common air pollutant that can impact personal health.  NO2 reacts with other airborne substances to form particulate matter and ozone, both of which have significant negative effects on respiratory health.  The US EPA has recently tightened standards for NO2. These newer standards will require increased monitoring of ambient air levels to ensure compliance. Implementing these new standards will, in turn, require increased training and proper calibration of equipment used to ensure the required accuracy. Alicat makes a range of products specifically designed to help state and local environmental analysts and technicians ensure the needed levels of accuracy.3

These experiments demonstrate the efficacy of the novel low-power FET sensor. The experiments were conducted using known gasses from commercial suppliers; control of the gas input was critical to making accurate assessments of FET function. Alicat Scientific Mass Flow Controllers were used to ensure the accuracy of these measurements by precisely regulating the input flow of the gas mixture. The extremely high controllable range of Alicat’s mass flow meters allowed control of flow rates from 1-100 sccm. Our latest flow controllers boast an increased controllable range of up to 10,000:1, which can be helpful for any experiment where a range of flow rates is required.

As scientists and engineers continue to develop novel sensors to enable IoT technologies, precise, reliable mass flow will continue to be required. At Alicat, increasing the pace of scientific innovation is our greatest passion. All of our instruments are custom built to the needs of your science and ship in days, months.

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

NEW HOLLOW SHAFT MULTI-TURN KIT ENCODERS FOR POSITION CONTROL APPLICATIONS

Slim Form Factor for Motor and Machine Manufacturers

POSITAL is introducing a new family of absolute rotary encoders for servomotors, stepper motors, robot joints and anywhere else a hollow center design is needed to achieve an optimal mechanical layout. Both single and multi-turn variants are available; for multi-turn models, the rotation counter is self-powered, using POSITAL’s Wiegand energy-harvesting technology. This eliminates the need for backup batteries and lowers maintenance costs.

  • Hollow Center Design for Optimal Mechanical Layout on Robotic Joints and Drives Shafts
  • 30 mm or 50 mm Internal Diameter Sizes Available
  • Battery-less Rotation Counter Based on Energy-Harvesting Technology
  • Capacitive Measurement System Allows for High Accuracy Even in Harsh Environments
  • Non-Proprietary Interfaces of SSI and BiSS C Standards

Capacitive Measurement Technology

These new products make use of a capacitive measurement system. Each encoder has two principle components, a stator and rotor, both containing specially shaped conductive surfaces. These surfaces, which function as capacitor plates, are positioned in close proximity. As the rotor turns, the patterns of the conductive surfaces change their relative position, causing changes to capacitive coupling in the system. This in turn causes changes to the amplitude and phase angle of a high-frequency electrical signal generated by exciter circuits in the stator. Special ASIC devices capture and decode these signal variations to determine the rotor’s angular position to a high level of precision.

Read more on the technology here.

The new POSITAL hollow shaft kit encoders offer excellent accuracy (+/- 0.02°) and dynamic response (up to 6000 RPM), making them suitable for use in critical motion control systems. However, what makes them especially useful in many applications is their shape. Both stator and rotor elements are in the form of disks with large central openings. This makes them an ideal choice in space-limited situations, such as servomotors, stepper motors or the joints in robotic arms , where it is desirable to have an embedded position sensor fitting around a central shaft or axle.

POSITAL hollow shaft kit encoders will be available in two sizes, with 30 mm or 50 mm internal diameters. Non-proprietary SSI and BiSS C communications interfaces are supported.

Energy Harvesting – No Battery

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The energy harvesting system is based on the Wiegand effect and eliminates the need for backup batteries or complex gear systems. 

Read More about the Wiegand Effect

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

Alicat Whisper Mass Flow Meters Lend Precision to Fiber Optic Process

by Ryan Barner

Fiber optic cables are highly desired for their speed of transmission and are growing as an industry. However, the industrial furnaces used for glass manufacturing require stable and repeatable control of gas for melt and annealing processes.

Preforms are the layered cylinders of glass, made on lathes using chemical deposition vapor flows, burners for heating and melting glass and pressure control to retain the shape while it is being formed. While the fiber drawing process means heating the end of a glass preform, and shaping the melting end into a cone that creates a continuous stream of molten glass which descends and cools into a fiber, which must then be guided in a way that will not break or alter it, while checking the thickness and adding layers to protect it.

Both require mass flow and pressure controllers that are fast, reliable and have high turndown ratios, all while functioning in potentially high temperature environments and compatibility with corrosive fuel gasses.

Industrial furnaces utilizing fuel gases for their burners exhibit low pressures.  Alicat Whisper series mass flow controllers offer a controllable range up to 1000 SLPM.  These flow rates can be achieved with a pressure drop across the Alicat MFC of as little as 1.65 PSI on our highest flow rate Whisper series controllers. This means even if the supply pressure is low, as fuel gases typically are, it is possible to control up to a full scale flow rate of 1000 SLPM.Alicat mass flow and pressure control instruments for glass and optical fiber manufacturing.

These low pressure instruments may also be deployed in annealing ovens and lehr ovens during the finishing process.  Using Alicat MFCs allow for control in each zone of the oven with repeatability and precision even if a low supply pressure is a requirement.  Ninety-eight gases and gas mixes are pre-programmed into an Alicat MFC providing options for variability in projects and processes.

Alicat MCW-series whisper mass flow controller, shown with optional backlit color display

In preform manufacturing, fiber drawing or ribbon forming processes – stable and fast mass flow and pressure control instruments not only ensure a better end product, but with Alicat devices, achieving these results is easier with our highly customized instruments and advice from Application Engineers.

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

ThermX

Industries Served
Our diverse temperature sensor product capabilities support a broad range of industries and applications. Several of our products can be applied into a variety of products or processes. Others are uniquely designed for a specific application. 

We can engineer a suitable temperature sensor into the most complex thermal heating and measurement requirement. Our technical expertise and production technologies, provide our design team with the flexibility to devise the most advanced sensing solutions, in the most practical configuration, and at the best value.

In addition to manufacturing temperature sensors, ThermX Southwest also distributes pressure, humidity, CO2 and flow sensors along with process control and data logging instrumentation. We also supply a wide variety of portable calibration equipment traceable to NIST. 
Industries served
Aerospace Pharmaceutical 
Semiconductor
Glass & Ceramics 
Metallurgical
Analytical Sciences
Material Sciences
Telecommunication
Power Generation 
Packaging Food & Beverage
Commercial Heating Medical
General Industrial 
Temperature Sensors
General Purpose Probes
High Temperature Thermocouples
Validation Thermocouples
Industrial Thermocouples
Insulated Wire Thermocouples
Thermocouple Rakes
RTD Probes
Thermistor Probes
Specialized Products
Thermocouple Wire
Calibration Services

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

Acceleration-Compensated Inclinometers Now With New Interface Option

ACCELERATION-COMPENSATED INCLINOMETERS 
NOW WITH NEW INTERFACE OPTION

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POSITAL FRABA has added a new communications interfaces for its innovative Dynamic TILTIX series – making it even easier to use these rugged instruments in mobile machinery and heavy commercial vehicles. Now available with either CANopen or SAE J1939 interfaces , these acceleration-compensated tilt sensors are able to deliver accurate measurement under the harshest operating conditions, including rapid motions, shock and vibration loadings.

  • Compensation of External Accelerations
  • Now Available with CANopen or SAE J1939
  • Clean Measurement During Dynamic Movements
  • Optional Output of Acceleration and Rate of Rotation
  • Well Protected up to IP69K
  • Compact and Robust Die-cast Housing with Integrated T-Coupler 
  • Wide Temperature Range from -40 to +85°C

Innovative Signal Processing Algorithms Reduce Signal Noise

The key to this remarkable dynamic performance is the addition of a second measurement system to the MEMS accelerometers used in conventional tilt sensors. An electromechanical gyroscope system was added to measure rate of rotational in the different axes. This eliminates the central shortcoming of conventional inclination sensors, where sudden accelerations or vibrations cause inertial loads in the accelerometers, adding noise to the output signals – and errors to the tilt angle readings. Signals from the accelerometer and gyroscope are combined by innovative algorithms to filter out the errors caused by acceleration loads so that the actual inclination is reported accurately. “What sounds so simple proved to be very time-consuming and labor-intensive in terms of practical implementation,” emphasizes Tobias Schubert, product manager responsible for POSITAL’s TILTIX inclination sensors. “We invested almost three years in the development of the algorithm alone. We worked extensively with pilot customers to assure ourselves that these instruments would work reliably under the harshest field conditions.”

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

Alicat Python and Python-driven command prompt

 by Bill Nick

Setup

Alicat Python and Python-driven command prompt (Windows Powershell) drivers have been developed principally by Pat Fuller at NuMat Technologies and are available for download from github.com: https://github.com/numat/alicat

In order to run the command prompt/Powershell driver, Python will first have to be installed on the computer. The latest stable Python 3 release is the recommended version to install: https://www.python.org/downloads/

Once Python has been installed, the simplest way to install the python/command prompt drivers is to command the following in the command prompt:

If the Python PIP package manager is installed and enabled, this is a simpler method:

Command Prompt (Powershell) Usage:

A menu of possible arguments and usage information within the command prompt can be accessed by entering “alicat –help” or “alicat -h”:

To poll an Alicat that is the only one connected to your target COM port, commanding only the port name will return data from the Alicat:

To poll a device with unit ID A, your command should look like this:

and the response from either of these commands should look similar to this:

Python Usage:

This command will open a serial connection to an Alicat device on the specified port:

If the Alicat is communicating on the specified port, it will return the same dictionary as when polled via Powershell.

Using this with Windows COM port COM1, for example, would look like this:

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

Universal Transducer Interface (UTI)

The Universal Transducer Interface (UTI) is a sensor-to-time signal converter, based on a self-calibrating period-modulated oscillator. Sensing elements can be directly connected to the UTI without the need for extra electronics. The output is digital and can communicate with any type of micro-controller. The UTI can operate in 16 different modes. To obtain accurate results in any of these modes, a reference element of the same kind as the sensor is required.

The UTI provides interfacing for all kind of resistive and capacitive sensors.

For convenient design-in, there is an evaluation board available. The UTI evaluation board and free down-loadable software ensure that custom applications will be up and running in no time.

Key Features

  • Accurate measurement of various sensors:
  • Capacitance values (2-300 pF, 14 bits)
  • PT100/1000 elements (14 bits 9 mK)
  • Resistive bridges (12 bits, resolution 700 nV)
  • Continues auto-calibration
  • Single power supply2.9-5.5V

Reference: click here.

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

Kits and Modules

We have developed a few modules that make designer’s lives easier and show off the great features of our sensors. Some of these boards are being used in measurement and production environments due to their ease of installation and the high quality of the outputs.

For the temperature sensors we offer the SMTAS04 and SMTAS08 boards. These boards can be connected to any PC using a USB cable – no extra power supply needed! These boards have high accuracy and great resolution (0.01C).

We have also developed a new UTI evaluation board; the UTI Evaluation Kit USB. This board is a real “plug and play” system. Very accurate capacitance and resistance values can be measured. Porting the very low output voltages of infrared sensors to other equipment is very challenging so we have designed an IIC interface module and USB module that make this very easy.

Key Features

  • Easy connect to pc/lt via USB
  • For 4 or 8 SMT172 sensors
  • From SMT172 to I2C
  • From SMT172 to SMT160
  • For UTI applications
  • Infrared modules with I2C (I2C to USB available)
  • Free software in the design notes

Reference: click here.

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

POSITAL AT SPS IPC DRIVES 2018

POSITAL AT SPS IPC DRIVES 2018

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From November 27 to November 29 we will be exhibiting at SPS IPC Drives in Nuremberg, the most important exhibition for the professionals in the Automation world.

You can find us in hall 7A booth 146. Make sure to try out our freshly baked waffles with cherries and cream!

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THIS YEAR’S HIGHLIGHTS ARE

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Kit Encoders for Servo and Stepper Motors

POSITAL’s new family of kit encoders provide the manufacturers of motors and other machinery with rugged, accurate and cost-efficient tools for building rotary position feedback into their products. The new kit encoders are based on POSITAL’s highly successful self-contained magnetic rotary encoders. Now however, the core components of these instruments are available as separate assemblies that can be readily integrated into other products.

POSITAL offfers now also through hollow kit encoders which are designed for installations where there are benefits to having the measurement element fit around a machine’s shaft or axle. The kit portfolio expanded to also include compact incremental optical kit encoders which are optimized for speed control of small drives, low power motors and stepper motors. These devices are simple, robust and easy to install,

  • Absolute Multiturn Without Battery or Gear
  • 17 Bit Resolution
  • Multiple Interfaces: BiSS-C, BiSS Line (One Cable Technology), SSI, Incremental
  • Quick, Simple Assembly and Disassembly
  • Mounting Compatibility with Common Incremental Kit Encoders

Read More

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Wiegand Sensors – Magnetic Pulse Generator

Wiegand sensor products from POSITAL reflect the knowledge from a full decade of experience using Wiegand-effect base revolution counters. The high performace sensors are assembled using SMD mounting technology and can be used for revolution counters in absolute rotary encoders as well as in other applications, e.g. gas or water meters.

  • Production Since 1974 – Started by John R. Wiegand
  • Proven In Encoders & Water Meters Since > 10 Years
  • Used In Access Cards For > 30 Years
  • Power Supply For Future IoT Applications
  • High Energy Output of ~170 nJ

Read More

tiltix_aks
Inclinometers with Dynamic Acceleration Compensation

POSITAL has introduced new versions of its TILTIX inclinometers that can provide reliable tilt measurement for moving equipment. These new devices use a combination of electro-mechanical accelerometers and gyroscopes to provide accurate measurements, even if the instruments are subject to strong accelerations.

  • Compensation of External Accelerations
  • Clean Measurement During Dynamic Movements
  • Optional Output of Acceleration and Rate of Rotation
  • Well Protected up to IP69K
  • Compact and Robust Die-cast Housing with Integrated T-Coupler
  • Wide Temperature Range from -40 to +85°C

Read More

Reference: click here.

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com

Customer needs translate to improved products

Andy Mangell

A guest blog from Andy Mangell. Andy is the sales director at Premier Control Technologies, a UK based process control technologies and products distributor which represents Alicat products. Andy has over 30 years of experience with pressure and flow control instrumentation. He can be reached at andymangell@pctflow.com.

Alicat Scientific’s standard product line is fast, versatile and tough. Their instruments make our customers’ jobs easier and more accurate, while reducing the number of instruments required. People love how easy they are to use and the short lead time between ordering and receiving the instrument. For both OEM producers and small research operations, Alicat’s ability to refine and customize instruments for their specific process is key to getting the best instrument to the customer. Listening to what customers need and anticipating improvements is how Alicat has been able to innovate and be the fastest mass flow controller company.

Since its foundation some 27 years ago, the concept of constant innovation and product development has been pivotal to the company’s remarkable success. Specifically, areas such as bi-directional mass flow measurement, precision pressure control within dead-ended non-flowing applications, multi-parameter measurement and control, true multi-gas capability and high turn-down have all benefited from the dedication to innovation.

Bi-directional mass flow measurement

By the application of either a positive or negative set-point signal, Alicat has enabled the possibility to control flows into a process in one direction first and then to switch into the opposite direction. Alternatively, flows can be controlled into a closed process and then vented without the need for additional bleed valves. Due to the inherently bidirectional nature of the Alicat sensor, the flow is measured in both directions and a net total provided if required.

Dual-valve precision pressure control

Precise control of pressure reduction and pressure relief valves from a single setpoint signal ensures process pressure remains stable, independent of other variables. Such processes as head space pressure control, glass reactor protection and the elimination of costly out-gassing through continuous bleed valves all benefit from this innovation. Alicat electronic pressure controllers provide responsive, stable control of absolute, gauge or differential pressures in dead-ended processes.

Multi-parameter measurement and control

Measurement of multiple parameters on the one instrument (mass flow, volumetric flow, temperature and pressure) enables the user to eliminate additional components within a system and the pipework/fittings required to install them, in addition to cables and electronic signal conditioning. All parameters are displayed on a single screen for easy monitoring of process gases or liquids. Any of the measurement parameters can be enlarged in the centre position for reading at further distances from the instrument. All of the displayed parameters are measured in real time, which allows you to look at the device display and quickly get an idea of how your process is operating. When a process begins to falter, this information can significantly reduce the amount of time it takes to diagnose and repair the failure. All Alicat mass flow controllers can be changed to pressure controllers or volumetric controllers via digital interface or via the display. The user can monitor mass flow while controlling pressure or vice versa.

True multi-gas capability

COMPOSER ™ gas mix composition software, available with color display

COMPOSER ™ gas mix composition firmware, shown on a color display

Following continuous innovation and development over the years, Alicat instruments are now preloaded with up to 130 full gas calibrations, thereby eliminating the additional measurement uncertainty introduced by conversion factors. Complete NIST REFPROP gas properties data has been loaded for each of the gases, ensuring that both the standard accuracy and optional high accuracy statements remain valid, regardless of the gas. The benefits to the user are significant. Instruments are no longer limited to just one application; once a certain project has been fulfilled, the MFC can be used again for a different project with different gases. Similarly, even within a single project, fewer instruments are required to meet the needs of multiple gases or multiple flow rates.

Wide turn-down range

Turn-down ratio is a measure of the usable range of an instrument, expressed as the full-scale range divided by the minimum point of measure. It indicates how much of the instrument range can produce accurate readings, which is very important when you want to measure or control a very wide flow range without having to change instruments. Most Alicat instruments have a turn-down of 200:1 as standard (i.e. as low down as 1/200th of the full scale), although with engineering collaboration and PD²I tuning this could be extended even further. As with multi-gas capability, the benefits are again significant: fewer instruments are required to cover a wide measured flow regime, and this results in cost savings for the user.

 

As a result of over two decades of development and innovation, a range of useful flow and pressure measurement and control devices has been established that, at their very core, have been designed to help the user make their life and work easier. This innovation will never stand still, and Alicat would welcome the opportunity to assist with any challenges you face and attempt to solve the impossible!

 

Reference: click here.

D&D Engineering – “W’ere YOUR Sensor Guys”
3835 E. Thousand Oaks Blvd. Suite 464 Westlake Village, CA 91362  – Voice: (818) 772-8720 Fax: (818) 772-2477 Toll Free: (888) 333-6474
Email: sales@sensorguys.com Website: www.sensorguys.com