ISA Webinar Recording: Temperature Measurement and Control

By Greg McMillan 1 Hour & 35 Minutes+

 

This educational ISA webinar on control valves was presented by Greg McMillan in conjunction with the ISA Mentor Program.

Greg is an industry consultant, author of numerous process control books, 2010 ISA Life Achievement Award recipient and retired Senior Fellow from Solutia Inc. (now Eastman Chemical).

The ISA Mentor Program enables young professionals to access the wisdom and expertise of seasoned ISA members, and offers veteran ISA professionals the chance to share their wisdom and make a difference in someone’s career.

Click this link to learn more about how you can join the ISA Mentor Program.

This video is freely available online at YouTube.com using the following link:
https://www.youtube.com/watch?v=GJY96uJLWow

Mercury Thermometer Alternatives by NIST

Promoting alternatives

no mercuryOnline —  The USA’s National Institute for Science & Technology (NIST) is not only  the nation’s National Metrology Institute (NMI), it also serves additional roles, including cooperating with other government agencies to safeguard people from harm due to sensors or practices that could be hazardous.

About 20 years ago the use of mercury-filled sensors, such as barometers, hygrometers and liquid-in-glass thermometers were recognized as sources of long-term hazards to man and nearly all animals.

The Federal Drug Administration (FDA) and Environmental Protection Agency (EPA) began efforts to ban the use of mercury in such devices and NIST has been in the forefront of the effort, along with volunteer organizations like ASTM International.

NIST has published a series of webpages that describe the issues related to mercury filled thermometers and considered several alternatives, some of which, in this Editor’s opinion are long overdue.

The rest of this article is copied from the December 22, 2016 NIST webpage: https://www.nist.gov/pml/sensor-science/thermodynamic-metrology/mercury-thermometer-alternatives-promoting-alternatives that begins the NIST series of information pages to help users understand some of the alternatives to mercury-filled  Liquid-in-Glass thermometers.

In effect these new temperature sensor alternatives bring many testing and measuring practices into the modern world of both sensor and display technologies, providing durability, precision and traceability along with digital options, in many cases.

Mercury-filled thermometers have historically served numerous industries as reliable temperature standards. Increased regulation and the high cost of cleaning up mercury spills have encouraged the use of alternative types of thermometers.

To support the use of alternative thermometers, the NIST Temperature and Humidity Group provides guidance documents, training, and technical consultation to other government agencies and standards-developing organizations.

Replacement of mercury thermometers with suitable alternatives will reduce releases of mercury into the environment and will reduce costs incurred to clean up mercury spills.

Historically, healthcare and regulated testing laboratories have relied greatly on NIST-calibrated mercury-in-glass thermometers as stable reference standards of temperature.

The use of mercury thermometers has been virtually eliminated in routine hospital use, but a wide variety of regulations and test methods continue to specify mercury thermometers.

Mercury thermometers have several intrinsic advantages:

  • they are stable for long periods,
  • failure is usually visually apparent, and
  • they require little training or maintenance.

 

However, mercury is a powerful neurotoxin, and the cost of cleaning a mercury spill in industry is many thousands of dollars. Furthermore, many states restrict the sale of mercury thermometers.

In 2008, the NIST Temperature and Humidity Group worked with several organizations to reduce or eliminate the use of mercury thermometers.

Environmental Protection Agency (EPA):  the EPA hosted meetings in the Spring of 2008 to discuss strategies to eliminate the use of mercury thermometers in EPA regulations and laboratories. NIST provided technical guidance documents, presentations, and technical advice as experts in temperature measurements.

Clinical Laboratory and Standards Institute (CLSI):  NIST Temperature and Humidity Group staff have worked with CLSI staff to update standards calling for the use of mercury-in-glass SRM thermometers, enabling laboratories to use other thermometer types with NIST traceability.

Centers for Disease Control and Prevention (CDC):  Control of temperature is critical to proper storage of vaccines, in order to preserve safety and efficacy. At CDC’s invitation, the NIST Temperature and Humidity Group gave a presentation at the May, 2008 “Vaccine University” that CDC sponsors. Over 60 participants learned how traceable temperature measurement and control can be achieved with modern electronic thermometers.

These activities build on support provided in 2007 to the Food and Drug Administration (steam processing of food) and ASTM committee D2 on petroleum.

In an environment of increased regulatory and economic pressures to discontinue the use of mercury thermometers, NIST has provided timely and critically important technical advice to other federal agencies and thermometer users, ensuring that important industrial and health-care temperature measurements are performed efficiently and accurately.

Major accomplishments:

  • Guidance document published on how to identify alternatives to mercury liquid-in-glass thermometers.
  • Technical support provided to other government agencies and to developers of documentary standards.

 

Links to other NIST webpages:

 

Selected Publications & Related Links

 

Questions about Mercury Thermometer Alternatives?

Temperature Measurement with your Computer

Windmill LogoOne of the best of our favorite resources on the Web is a software company on Manchester, England, Windmill Software. They have supplied free PC software for Test & Measurement to all who wish to download it from their website: http://www.windmill.co.uk,

Windmill has for many years also published a free monthly informative eNewsletter called Monitor newsletter (ISSN 1472-0221); archive and subscription available online at http://www.windmill.co.uk/newsletter.html.

At last look it was up to issue No, 224!

Here’s links to one of the extra specials they have done on the subject of temperature measurement

(Excerpt)

Measuring Temperature with a Computer

Temperature measurement is the most common application of data acquisition systems. You will need a device to measure the temperature – a temperature sensor. Thermocouples, resistance temperature devices (RTDs), thermistors, platinum resistance thermometers and infrared thermometers are all types of temperature sensor.

The most popular are thermocouples and RTDs. The sensors you choose depends on several things, such as as your expected maximum and minimum temperatures, cost, accuracy needed and your environmental conditions.

To get data from the temperature sensor into your PC you need a data acquisition interface with suitable software. The interface unit plugs into your computer, for example into the USB or Ethernet port.

You wire the sensor to the interface, install the software and the computer can now monitor temperatures.


Comparison of Thermocouples and RTDs

IMPROVING HUMIDITY MEASUREMENTS IN METEOROLOGY

A product with a unique advantage

EE33 sensor tube - thermal image
EE33 sensor tube – thermal image

Air humidity and temperature play an important role in meteorology. Highly accurate measurements of these climate parameters form the basis of accurate forecasts and meaningful records.

The E+E Elektronik Model EE33 series humidity and temperature sensor is the only one on the market with a double-heated probe. Both the sensor tube and the sensor element are heated.

An application note, free for download from their website, tells the rest of the story.

You can download it be clicking here.

If that does not work, as sometimes happens when organizations “refine” their websites, we have archived a copy in our database; it may be downloaded here: Humidity_measurement_meteorology

Related technical webpages & download from E+E Elektronik:

E+E Elektronik – the Sensor specialist for humidity sensors, CO2 sensors, moisture in oil, dew point, air velocity, flow and temperature sensors. As a specialist for sensors E+E Elektronik produces humidity sensorsCO2 sensorsflow sensors, transmitters, hand-held meters and  dataloggers for the measurement of relative humiditymoisture in oildewpoint,
air velocityflowCO2 and temperature. E+E also operates a nationally accredited calibration lab and is appointed to maintain the “National Standard for Humidity and Air Flow Speed in Austria”

World HQ

E+E Elektronik Ges.m.b.H.
Langwiesen 7
A-4209 Engerwitzdorf
Austria

Tel: +43 (0)7235 605-0
Fax: +43 (0)7235 605-8
E-mail: info@epluse.com
Website: www.epluse.com

USA

E+E Elektronik Corp.
124 Grove Street
Franklin, MA 02038
United States

Tel: +1 508 530 3068
Fax: +1 508 346 3798
E-mail: gleighton@epluse.com

TI Temperature Measurement Videos

TI, or Texas Instruments, is one of the world’s most prolific and largest makers of temperature sensors. They make all kinds but their sensors are mostly in the form of Integrated Circuit semiconductors.

TI also does an exceptional job in educating users how their devices work and how they can be interfaced and incorporated in measurement systems. Especially useful are the videos showing how some of their other integrated circuit modules can be used with external temperature sensors, like Thermocouples, RTDs and Thermistors.

Here’s an example of an interesting one:

Developed through TI’s expertise in MEMS technology, the TMP006 is the first of a new class of ultra-small, low power, and low cost passive infrared temperature sensors. It has 90% lower power consumption and is more than 95% smaller than existing solutions, making contactless temperature measurement possible in completely new markets and applications.

Check out their Video Channel on YouTube, especially the long list of videos already published about “Temperature Measurement”. It very straightforward; just go to: https://www.youtube.com/user/texasinstruments/search?query=%22temperature+measurement%22

Thermocouple 101

The Analog Devices’ 8 Video Series on Thermocouples

This informative, basic series of brief videos on YouTube and linked on the AD website seems to lack an index. Below there is an approximation to what we believe the staff at AD intended followed by a series of 8 pages, one for each video on YouTube.com

Index

  1. Thermocouple 101: What is a Thermocouple?
  2. Thermocouple 101: Measuring the Tiny Signal
  3. Thermocouple 101: Cold Junction Compensation
  4. Thermocouple 101: Setting the Common Mode Voltage
  5. Thermocouple 101: Open Thermocouple Detection
  6. Thermocouple 101: Filtering a Thermocouple
  7. Thermocouple 101: Thermocouple Nonlinearity
  8. Thermocouple 101: Compensating for Nonlinearity

What is a Thermocouple?

Read more Thermocouple 101

New ASTM Standard For Digital Thermometers

ASTM E2877, Guide for Digital Contact Thermometers

Digital Display with Temperature 27 Deg. C by palomaironique
Image Courtesy of OpenClipArt.org

W. Conshohocken PA, USA — A new ASTM International standard provides a variety of recommendations for the manufacture and selection of digital thermometers. ASTM E2877, Guide for Digital Contact Thermometers, was developed by Subcommittee E20.09 on Digital Contact Thermometers, part of ASTM International Committee E20 on Temperature Measurement.

Included in ASTM E2877 is a set of accuracy classes for digital thermometers. These classes pertain to the temperature interval from -200 °C through 500 °C, an interval important for many thermometry applications.

In order to qualify for a specific accuracy class, a thermometer must measure correctly to within a specified value over this interval or the subinterval in which the thermometer is capable of making measurements.

Digital thermometers that are used for measuring temperature in many laboratories and industrial applications are being increasingly seen as environmentally safe alternatives to mercury-in-glass thermometers, particularly since the U.S. Environmental Protection Agency’s efforts to phase out mercury thermometers are under way.

According to Christopher W. Meyer, a physicist at the National Institute of Standards and Technology, and an E20 member, the petroleum industry and others have used mercury thermometers for decades.

“These industries wish to convert to digital thermometers but until now there has been no ASTM standard for them,” says Meyer. “Also, there has been no set of defined accuracy classes that could help specify the type of thermometer needed for a given application. ASTM E2877 is necessary for instructing these industries in the basics of digital thermometers and for providing a standard that can be used in operation protocols.”

The new standard describes three types of sensors used in digital thermometers: platinum resistance sensors (PRTs or RTDs), thermistors and thermocouples (TCs).

“ASTM E2877 describes the various types of contact digital thermometers that are on the market and discusses the relative characteristics of each,” says Meyer. “It also defines a set of accuracy classes for digital thermometers that may be used to help specify the type of digital thermometer needed for an application. It will allow industries that have previously specified mercury thermometers in their protocols to use digital thermometers.”

All interested parties are invited to join in the standards developing activities of E20.09.

To purchase ASTM standards, visit www.astm.org and search by the standard designation, or contact ASTM Customer Relations (phone: 877-909-ASTM; sales@astm.org). ASTM International welcomes participation in the development of its standards. For more information on becoming an ASTM member, visit www.astm.org/JOIN.

For more news in this sector, visit www.astm.org/sn-consumer or follow ASTM on Twitter @ASTMProductsRec.

ASTM Committee E20 Next Meeting: May 20-21, 2013, May Committee Week, Indianapolis, Ind.

Technical Contact: Christopher W. Meyer, National Institute of Standards and Technology, Gaithersburg, Md., Phone: 301-975-4825; cmeyer@nist.gov

ASTM Staff Contact: Christine DeJong, Phone: 610-832-9736; cdejong@astm.org

ASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognized leader in the development and delivery of international voluntary consensus standards. Today, some 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence.

ASTM’s leadership in international standards development is driven by the contributions of its members: more than 30,000 of the world’s top technical experts and business professionals representing 150 countries. Working in an open and transparent process and using ASTM’s advanced electronic infrastructure, ASTM members deliver the test methods, specifications, guides, and practices that support industries and governments worldwide.
Learn more about ASTM International at www.astm.org/ABOUT/overview.html.

Using a 3-Wire RTD to Reduce Temperature Measurement Errors

Ensure High Accuracy in Your Critical Temperature Measurements

DataloggerCHESTERLAND OH, USA — To prevent inaccurate temperature measurements which can potentially cause disastrous inventory losses, CAS DataLoggers recommends using 3-wire RTDs to customers taking temperature measurements using RTD sensors.

These sensors are affordable and easily available for use with our wide inventory of temperature dataloggers, but some users are unaware of this more accurate option. With this in mind, Applications Specialists have put together this brief guide to show the need for 3-wire RTDs.

RTD sensors make simple resistance measurements, usually at about 100 ohms, which is a relatively low level of resistance. Therefore an RTD measurement error of 1 ohm or more is quite significant, for a regular RTD at room temperature, the resistance is 109.1 ohms, and even a 1-ohm error in that measurement will cause a temperature error of about 2.5 °C.

When using a 2-wire RTD, users may find that the resistance of the connections between the sensor and datalogger directly affects the temperature measurement, so this is easily avoided by using a 3-wire RTD, which enables the connected datalogger to compensate for the resistance of the circuit.

An example of this kind of measurement error occurs when connecting an RTD to a piece of 20 AWG (American Wire Gauge) copper hookup wire (solid or stranded), with electrical resistance* of about 1 ohm per 100 ft. of length.

In this case, using a 2-wire RTD with a 50-ft cable on it can result in a 2 ° to 2.5 °C systematic temperature error just due to the resistance of the wire.

So, especially with longer cable runs, users can avoid this significant error source by using a 3-wire RTD sensor along with a data logger that provides automatic compensation for these types of applications.

* Reference the electrical resistance of copper wire versus AWG size on the HyperPhysics website at: hyperphysics.phy-astr.gsu.edu/hbase/tables/wirega.html (NOTE:  HyperPhysics is a free online educational resource by Dr. Rod Nave at the Georgia State University in Atlanta GA, USA.  A CD/DVD version  is available for purchase at: http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html#ahph. Apps for iPhone and iPad are also available at small or moderate cost at Apple’s iTunes store.)

CAS DataLoggers products are used in a wide variety of applications in remote monitoring, in industrial process and manufacturing industries, for automotive and aerospace data collection, in pharmaceutical manufacturing and storage, and in geological and environmental monitoring—there are even units on the Space Shuttle and ISS (International Space Station)!

Sophisticated data acquisition and control systems are also available including high performance real-time systems for situations where traditional test systems or programmable controllers are not suitable.

These systems are used in data acquisition, test and control applications where microsecond precision is needed. Models are available with 8 to over 400 analog input channels, analog output channels, digital inputs and outputs, counters, RS-232, RS-485 CANbus and Profibus interfaces. CAS DataLoggers also provides configuration assistance, custom programming, custom system design and assembly, post-sales technical support, and repair and calibration services. Development capabilities include custom data acquisition and data logging systems, test and measurement systems, and portable data collection systems.

For more information on a wide range of temperature dataloggers from Accsense, T&D, Grant and more, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Applications Specialist at (800) 956-4437 or visit the website at www.dataloggerinc.com.

Contact Information:
CAS DataLoggers, Inc.
12628 Chillicothe Road
Chesterland, Ohio 44026

Tel: +1 (440) 729-2570 and, Toll-free: (800) 956-4437
Email: sales@dataloggerinc.com
Website: www.dataloggerinc.com

Data Translation, Inc.

dtlogo

Data Translation,founded in 1973 and headquartered in Marlboro, Massachusetts, USA, is a leading designer, manufacturer, and provider of data acquisition solutions for test and measurement. With expertise in the design of high-accuracy, high-quality hardware and application software, Data Translation partners with end users and OEMs to achieve their test and measurement goals.
Data Translation has a worldwide presence, with offices in the US and Europe and distribution in more than 40 countries. Data Translation products are manufactured in the USA.

USB Data Acquisition

Ethernet Data Acquisition Read more Data Translation, Inc.

Thermalogic Corporation

Cost Effective Solutions For Temperature & Humidity Measurement & Control

thermalogic_logo_img

Hudson MA, USA —  Thermalogic® Corporation began in 1971 as a supplier of rugged, encapsulated analog temperature control modules, which are still an ideal solution for numerous control situations. Their line of control/sensor designs and products has steadily expanded over the decades, providing cost effective solutions ranging from large multiple zone digital to tiny analog controls and extensive sensor capabilities tailored to exact job requirements.

Thermalogic® customers comprise a cross section of industry and business, including food processing and service, test equipment, fabrication machinery, rail transportation, cooling and heating equipment, semiconductor processing, agriculture, environmental treatment, and laboratory apparatus.

The full range of Thermalogic® service is performed in-house, including R&D, analysis of customer requirements, product design, manufacturing, quality control, and warranty maintenance.

Their products include: Read more Thermalogic Corporation