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Teledyne Hastings Instruments Blog

Doug Baker

Recent Posts

Sulfur Hexafluoride Gas (SF6)

Posted by Doug Baker on Wed, Jul 29, 2020 @ 03:14 PM

Over the next several blogs, we will be discussing various industrial gases. While some of these (carbon dioxide, argon, methane, and hydrogen) may be very familiar to our readers, other gases may not be as well known. In this blog, we will take a look at sulfur hexafluoride (SF6), a gas that is one of the most important today in the utility industry.


SF6 is an interesting gas primarily because of its electrical properties. Certain neutral gas molecules can easily capture free electrons and form stable negative ions. The efficiency of negative ion formation in a gas is determined by its electron affinity. SF6 , it turns out, has a very high electron affinity and therefore has excellent electrical insulating strength. So, in an electrical discharge inside a volume containing SF6 gas, the free electrons generated by the discharge are captured by neutral SF6 to form negative ions. These large negative ions are not able to travel quickly and so the discharge is usually quickly extinguished. One other note about SF6, the insulating property of the gas improves with increasing pressure. SF6 is colorless, odorless, non-toxic, and non-flammable. As you can see, these properties make it very useful to the generation, transmission, and distribution of electricity. 80% of the world’s SF6 gas is used by electrical utilities in circuit breakers, transformers, and gas insulted switches.

SF6 is arranged in a hexagonal structure. Each of the six fluorine atoms shares two its electrons with the outer shell of the sulfur atom in the middle. This structure gives SF6 its stability over a broad range of temperatures; the gas is thermally stable up to 500°C.


Power Substation

SF6 is often used in high voltage breakers. One example is the so-called dead tank breaker. In a dead tank breaker, the tank is electrically tied to earth/ground. In the live tank version, the tank is floating at a higher voltage.


The “make/break” mechanism of the breaker is shown in the diagram below. As noted above, the insulating properties of SF6 are improved with increasing pressure. So one of the jobs of the breaker’s piston actuation is to compress the SF6 gas and force it to flow into the arc region. As the contacts are moved apart, current will try to continue to flow as an arc. Any resulting arc is quickly extinguished by the pressurized SF6 flowing into the region. Incidentally, during breaker manufacturing, vacuum gauges from Teledyne Hastings are used to measure vacuum levels inside the vessel during pump down as the air is removed. After evacuation, the region can be filled with SF6.  

SF6 Circuit Breaker

OK, one last note about SF6 to conclude this blog and this falls under the category of “Don’t Try This at Home.” Just like Helium will make your voice sound higher if inhaled, SF6 will make your voice sound lower. You can find many demonstrations of this on YouTube. The most famous example is probably the demonstration on “The Big Bang Theory.” However, SF6 is one of the most powerful greenhouse gases and its release into the atmosphere should be minimized.


300 Vue Gas screen-1

Teledyne Hastings builds both vacuum and flow instrumentation which can easily work with SF6. Note that SF6 has a very high thermal conductivity. Conceptually, this makes sense because the gas molecule has many degrees of freedom – translational, rotational, and vibrational.  The GCF (gas conversion factor) for SF6 use with the 300 Vue line of flow controllers is 0.27. In other words, if you wanted to use a 300 Vue mass flow meter that had been set up for nitrogen, you would need to multiply the output by the 0.27 GCF. The good news for you is that with the 300 Vue, you can just select the gas from the front panel as shown in the photo below. Just keep in mind that if you wanted to do this, the required pressures for the valve are going to be different. You will likely need a higher pressure drop. But as always, our application engineers can be reached by email, phone, or Live Chat on our website: www.teledyne-hi.com

How Vacuum Gauges are used in the production of Neon Lights

Posted by Doug Baker on Wed, Jul 01, 2020 @ 01:48 PM

Several months ago, I saw an interesting article about a cool museum called the Neon Museum which is located in Las Vegas.


According to the museum’s website, “the Neon Museum is a non-profit 501 (c) 3 organization dedicated to collecting, preserving, studying and exhibiting iconic Las Vegas signs for educational, historic, arts and cultural enrichment.” The museum holds over 250 neon signs. Tours are given both day and, of course, at night. The main collection in the “Bone Yard” includes signage from Caesar’s Palace, The Stardust Resort and Casino, and the recently added giant guitar from the now closed Hard Rock Café.

Some of the pieces are still operational and “live” shows are given nightly. Other signs are dormant and are lit up by flood lights.


(Photos Courtesy of the Neon Museum, Las Vegas, NV)


Production of neon light tubes requires vacuum pumps and, of course, reliable vacuum measurement. Typically, glass tubes are bent into shape and then pumped to around 1 Torr and energized using a glow discharge to clean up the tube. Next, the tube is evacuated to the mTorr region. Different gases are then backfilled to a few Torr which, when excited in a glow discharge, create various colors. Neon gives the classic neon red/orange glow while carbon dioxide produces white, helium gives yellow, and mercury can be blended with neon to produce blues. In some cases, coatings on the internal surface of the glass can be used to create additional colors. When using coatings, mercury is included in the gas to ensure that UV photons are created to activate the fluorescent coating.

A nice tutorial of glow discharge characteristics with some history is given starting on page 14 in the February 2020 issue of Vacuum Technology & Coating magazine.  https://digital.vtcmag.com/12727/26337/index.html

HVG 2020B Angle Finger 20.9CThe new HVG-2020B from Teledyne Hastings is a great vacuum gauge for this application. The gauge uses two vacuum sensors: a piezoresistive sensor to measure pressures from atmosphere to 10 Torr and a thermal Pirani sensor to measure from 1 Torr to 0.1 mTorr. In between 1 and 10 Torr, the gauge uses a weighted average to ensure a smooth transition between the two sensors. The piezoresistive sensor is gas species independent, so no matter what gas is being backfilled, the piezoresistive sensor gives an accurate measurement. The Pirani sensor’s response is affected by the gas species, but the user can select a gas and the correction is made.


So, the next time you see a neon light, you can think about the vacuum gauge that was probably used to manufacture the gas tube. And if you’re ever in Vegas, check out the Neon Museum!


For more information about any of our vacuum gauges or our complete line of mass flow meters and controllers, we are here to help. You can contact us at hastings_instruments@teledyne.com , Live Chat on our website www.teledyne-hi.com , or call 757-723-6531 (800-950-2468). And to learn more about the HVG-2020B Vacuum Gauge, click the link below, “5 Reasons you need the HVG-2020B Vacuum Gauge.”

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Tags: Vacuum gauge

Can Smartphones Actually Measure Pressure?

Posted by Doug Baker on Wed, Apr 17, 2019 @ 08:58 AM

Flow Converter App - iphoneRecently, I learned that certain smartphones contain an actual pressure transducer. I shared this info with a friend who insisted that the phone was not really measuring pressure, but was instead using the internet to download the pressure based on the phone’s location. Now, I had to prove them wrong.


So, I did what I thought was the obvious proof… I placed my phone in a small test chamber (i.e. a bell jar as shown in the photo below), and then pumped the system down to show that the readings were, in fact, generated locally. I captured this all on video - see below.  Note: It was hard to get a good image of the phone inside because of the protective cage surrounding the glass bell jar.

 Bell Jar  
Smart Phone in Vacuum 190412

I used a free barometer app to get the pressure readings. In addition to a dial type readout, the app gives a nice trend line (pressure vs. time). Also, the app allows the user to adjust the time scale. During a recent flight, I used the app to record changes in cabin pressure. (My ears are also painfully good at detecting swings in cabin pressure!)


Now, you may be wondering why a smartphone would include a vacuum/pressure transducer. In addition to using the changing barometric pressure as an indication of weather, the pressure transducer readings can be used to provide the user’s altitude when hiking, cycling, or climbing. The formula to convert pressure to altitude at low altitudes is fairly linear. 

HVG 2020A_76307_fingerSo, it is true that you may be able to use your smartphone to measure vacuum in your system. However, we would like to suggest an easier way… check out our new HVG-2020A (“2020 Vision”) vacuum gauge. This gauge measures from just above atmospheric pressure (1000 Torr) to below 1 Torr with an accuracy of ±(0.1% of Reading + 0.5 Torr).

The gauge features an optional color touchscreen display which has several different modes including pressure vs. time. It provides analog output (0-5 VDC, 0-10 VDC, 4-20 mA,…) as well as digital output (RS232, RS485, USB) and with our FREE Windows™ software, it is super easy to collect and store data.

For more information about any of our vacuum gauges or our complete line of mass flow meters and controllers, we are here to help. You can contact us at hastings_instruments@teledyne.com  or call 757-723-6531 (800-950-2468) or click the button below.

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Tags: vacuum pressure

Teledyne Hastings Instruments’ Glass Shop and the DB Series of Reference Tubes

Posted by Doug Baker on Mon, Mar 04, 2019 @ 01:57 PM

75th Anniversary LogoThis year, 2019, marks the 75th anniversary of Hastings Instruments and we will be celebrating all year long by discussing some of our past while focusing on our future. This month, I’d like to tell you a little about our glass shop.


Robert H Work Company glass workers 1966

In 1966, Hastings-Raydist purchased the Robert H. Work Company. Work had been a supplier of glass parts for Hastings. The company was then moved into the Hastings plant. At the new location, glass workers began to produce scientific glassware under the Hastings label. Product catalogs in the late 60s and early 70s included McLeod vacuum gauges, calibrated gas leaks, and Pyrex vacuum gauge tubes.


Today, we still use our glass shop to build the Hastings Reference Tube. A reference tube is an evacuated, sealed vacuum gauge tube accurately marked at a specific pressure. It is electrically equivalent to our most popular vacuum gauge tube families.

Gauge Tube Family


Reference Tube


Reference Tube Family



DV-4 Series (Purple)

20 Torr


DV-5 Series (Red)

100 mTorr


DV-6 Series (Yellow)

1000 mTorr


A reference tube can be used with several of our thermal vacuum gauge instruments including the HPM-4/5/6, the VT and CVT, the DVT and DCVT, and even the DAVC controller. 

HPM 456 rt CVT DIG VT Teledyne Hastings DigitalAVC

How is it used? Simple, you just plug in your reference tube and compare the reading from your instrument with the number that is shown on the reference tube label. 
Reference Tube enlarged bubble

So the reference tube tells you that your electronics and cabling are working correctly. Note that a reference tube will not directly tell you anything about the state of your gauge tube. But through process of elimination, you can often determine that the gauge tube needs to be replaced. You can learn more about troubleshooting thermocouple vacuum gauges here:


As noted in the table above, the reference tubes, like the gauge tubes, are color-coded. And reference tubes can be sent back to us to be recertified which many folks do on an annual basis.

Next, let’s discuss a little about what is going on inside of a reference tube. Sometimes people will ask if we adjust the pressure inside the tube to allow it to read a certain value – we do not. In other words, if you could measure the pressure in the sealed-off tube, it would not be the pressure reading that is stated on the side of the reference tube. While a reference tube does have the same thermopile sensor arrangement, it is simply trimmed to give a particular reading when powered by the correct heater voltage.

Hastings Craftwork todayWe are proud of our long history of quality craftwork, not only in the glass shop, but throughout all of our vacuum and thermal mass flow product lines here at Teledyne Hastings. The same tradition of quality goes into our newest products including the 300 Vue line of mass flow controllers and the HVG-2020 Vision line of vacuum gauges. You can learn more about our products by visiting www.teledyne-hastings.com




Tags: Gauge Reference Tubes

Mass Flow Controller Calibration Report - What Does it Mean?

Posted by Doug Baker on Thu, Aug 23, 2018 @ 10:15 AM

In this short blog, we are going to look at one of our mass flow controller calibration reports and discuss some of the terms that you will see. There is good information at the bottom of these reports, so let’s jump in and take a closer look…

Sample Calibration Report

At the bottom of every one of our calibration data sheets, you will see the following statement:

This calibration complies with ANSI/NCSL Z540-1-1994 and ISO 17025-2005 [non-accredited] and is traceable to the National Institute of Standards and Technology. This validation was accomplished by qualified personnel directed by controlled procedures. The accuracy of this calibration for any gas other than the actual gas used may be subject to theoretical corrections. Customer Service can be contacted weekdays 8AM-5PM EDT at 1-800-950-2468.

Let’s start with part of the first sentence, “This calibration complies with ANSI/NCSL Z540-1-1994 and ISO 17025-2005 [non-accredited]”  According to the NCSLI webpage , there are two national standards for calibration laboratories. These are Z540-1 and ISO 17025. There are some differences between the two standards. And the aforementioned NCSLI gives a detailed description of both. In short, 17025 is appropriate for both calibration and testing labs whereas Z540-1 addresses calibration labs only. 17025 requires that the laboratory be a legal entity that can demonstrate competency, which includes thorough analysis of the uncertainty associated with the calibration services. Another difference between the two standards is that 17025 places the responsibility of the calibration due date on the end-user. In other words, the calibration lab should not determine the customers calibration cycle. That is why you no longer see calibration due dates on Teledyne Hastings’ labeling.

OK…. if 17025 is the latest, greatest, and accepted around the world, why do we still even list Z540-1 on our calibration reports? Because, we still have customers who adhere to Z540-1 and need the statement on their paperwork.

What about the word “non-accredited” that appears in parentheses? While we strive to conform to ISO 17025, which includes rigorous internal audit review, it has been our position that as a manufacturer, it is not necessary / appropriate for us to invest in the accreditation activities and third party audits. However, we do recognize the depth and critical nature of the standard.  Because of those criteria, we have chosen to compose our procedures and train our personnel to be in compliance with the standard. So to be clear, Teledyne Hastings is not accredited to ISO 17025.

Let’s move on… what do we mean by, “…traceable to the National Institute of Standards and Technology”? Simply this, we can provide an unbroken chain of calibration documents that connect your calibration back to NIST, the National Institute of Standards and Technology.


Now here is a trick question… does a NIST traceable calibration tell us anything about the uncertainty of the calibration? The answer is, “no”. For example, we could calibrate one of our most advanced mass flow controllers, the HFC-D-302B 300 Vue which has a stated uncertainty of ± (0.5% of Reading + 0.2% of Full Scale).

– or we could calibrate our HFC-202 flow controller (±1% of full scale using the same metrology and the stated uncertainty for each instrument would be the same as before. In other words, the performance of these instruments does not improve just because a NIST traceable standard was used.

One more note, some customers request “Backup Documentation” to their calibration data reports. In other words, they want copies of the calibration reports of our metrology that form the unbroken link from their calibration back to NIST.  There is a nominal administrative fee to collect, scan, compile, and email these calibration reports for each individual piece of metrology that was used.

stackes of paper

Does everybody need the Backup Documentation? Usually not, but enough customers request these so it is a service that we offer.  Quite often the reason why our first tier customer will request the additional supporting calibration reports is because they are manufacturing complex assemblies that their higher tier customers are procuring with the aforementioned unbroken chain back to NIST as a purchase order flow down requirement.

Next, we have the sentence, “This validation was accomplished by qualified personnel directed by controlled proceduresThis gives us an opportunity to tell a little about our ISO 9001:2015 Quality System. As a key part of our system, all assembly and calibration personnel must complete rigorous training and demonstrate proficiency before working on either the Flow Products or Vacuum Products Teams. Also, every product or subassembly acceptance test, that has a measurable output, is controlled by a top tier Quality System Procedure. The procedures, training program, in fact the entire Quality System is subject to routine internal audit program, third party surveillance audits, and third party ISO 9001:2015 certification audits.

ISO Certificate

Now what about the statement, “The accuracy of this calibration for any gas other than the actual gas used may be subject to theoretical corrections”?  There are certain gases which are hazardous and/or corrosive. While our flow meters and controllers are quite suitable for use in many of these gases, there are several of the gases that we have never (and will never) allow into our facility. So, we use theoretical corrections to map the output of our flow products using the calibration gas to the output for the user’s gas.

We are very proud of our metrology and quality programs. And we welcome your questions. If you have a question about mass flow controllers, vacuum gauges, or just want more information about a Calibration Report, we are here to help. You can contact us at hastings_instruments@teledyne.com  or call 757-723-6531 (800-950-2468).

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Tags: mass flow controller

What is a Vacuum Furnace, How Does it Function, And How is it Used?

Posted by Doug Baker on Thu, Jun 21, 2018 @ 09:58 AM

Teledyne Hastings is working to expand our throughput so that we can better serve our customers by meeting increased demand while decreasing lead times. Over the last several months, we have added and improved calibration systems in both our vacuum and flow production areas. We have also purchased a new vacuum furnace which increases our production capacity. In this blog, we will describe what a vacuum furnace is, how it functions, and how we use it.

A picture of our newest vacuum furnace is shown below.  The three major components of the vacuum furnace, from left to right, are the high-speed diffusion pump, the vacuum chamber with a high temperature hot zone, and the control cabinet. The diffusion pump is capable of pumping 180,000 lpm.  While the pumping speed may seem unnecessarily high for the given volume, keep in mind that the gas load, at high temperature, can be very high. The diffusion pump is connected to the hot zone chamber via a large right angle vacuum valve. The diffusion pump is backed by a rotary vane vacuum pump. Pressures in the foreline can be monitored by using a Teledyne DV-6R vacuum gauge tube. The base pressure of the system, with the heat zone at room temperature approaches 1 x 10-6 Torr.

Vacuum Furnace

 Leon Whitehead at the controls of the new vacuum furnace.

The hot zone is the heart of the vacuum furnace. A picture showing the inside of the hot zone is shown below. The effective hot zone size is 12”w x 12” h x 24” d. The molybdenum rod elements inside the hot zone are resistively heated once the system has reached sufficient vacuum. Under vacuum, the hot zone can reach temperatures exceeding 1300°C (2372°F).

Inside of Hot ZoneInside the hot zone. Note the series of Molybdenum rod elements.


The vacuum furnace is controlled by a touchscreen panel with PLC. The operator can select and execute a pre-programmed temperature/time profile for a given task. In addition, pressure and temperature at various locations on the system are monitored and displayed. The control cabinet also includes the transformers, contactors, and fuses. 


Teledyne uses our vacuum furnaces for both fusing and brazing operations - all while precisely controlling the environmental conditions within the hot zone. In a typical schedule, the system is pumped out to its base pressure and then the hot zone is brought up to 800°C. After reaching this temperature, the hot zone is held for a period of 20 minutes. Next, the hot zone is slowly ramped to 1100°C, which takes about an hour. The hot zone is then held there for up to 1 ½ hours.

Teledyne Hastings Instruments is an ISO 9001:2008 certified manufacturer and we produce a complete line of instruments for precise measurement and control of vacuum, pressure, and gas flow. Our vacuum furnaces and the corresponding Quality Work Instructions deliver consistent results, which in turn provide our customers with high quality instrumentation. For information on Teledyne Hastings and our Mass Flow Meters and Controllers or Vacuum Gauges, please visit www.teledyne-hi.com or click the button below.

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Tags: vacuum gauges, vacuum meters

Digital Flow Meters and Controllers now protected against dust and water - what that means for you!

Posted by Doug Baker on Thu, Mar 08, 2018 @ 08:39 AM

300 and IP-67.jpgTeledyne Hastings designs and build mass flow controllers for a broad array of markets from clean laboratory environments to heavy industrial installations. Recently, we have been asked to provide our newest line of Digital 300 Flow Meters and Controllers into more demanding environments. And, we are proud to offer an optional IP-67 enclosure, which provides protection against dust and water. More on our product later in the blog.

But first, let’s explore the IP, or Ingress Protection, rating system.  NEMA (National Electrical Manufacturers Association) publishes a standard (ANSI/IEC 60529-2004) entitled, “Degrees of Protection Provided by Enclosures (IP Code)”. The corresponding international standard is IEC 60529. The introduction to the IP Code starts:


This standard describes a system for classifying the degrees of protection provided by enclosures of electrical equipment for two conditions: 1) the protection of persons against access to hazardous parts and protection of equipment against the ingress of solid foreign objects and 2) the ingress of water.


The IP Code rates the degree of protection by using two numbers. The first number describes protection against solid particles; the second number describes protection against liquids. The Wikipedia page describing the IP Code provides a couple of nice tables to help us quickly understand the numbers.

Dust (First Number) Moisture (Second Number)

IP 0x - No Protection

IP 1x - Objects > 50mm

IP 2x - Objects > 12mm

IP 3x - Objects >2.5mm

IP 4x - Objects > 1mm

IP 5x - Dust Protected

IP 6x - Dust Tight

IP x0- No Protection

IP x1 - Vertically Dripping Water

IP x2 - 15 Degrees Tilt Dripping WAter

IP x3 - Sprayed Water

IP x4 - Splashed Water

IP x5 - Water Jets

IP x6 - Powerful Water Jets

IP 7x - Effects of Immersion

IP x8 - Indefinite Immersion

IP x9 - High Pressure, High Temperature Water Jetting

IP-67 in aquarium.jpgWhich now brings us back to the Teledyne IP-67 rated enclosure. The first number, “6”, indicates that our enclosure is completely protected against dust. The second number, “7”, indicates that our instrument can withstand submersion in water up to a meter in depth for up to 30 minutes.

One side note about IP ratings, if you follow the battle between Samsung Galaxy and Apple iPhone, you may have seen an article published by CNET last September (2017). In the article, it was stated that the iPhone 8 and 8 Plus are certified with an IP67 rating, while the Samsung Galaxy S8 is rated IP68. And by the way, yes… according to Reddit, the whole putting the wet iPhone in rice thing to dry it out, does work.  

In order to claim the IP-67 rating, Teledyne Hastings has sent test instruments to NCEE Labs in Lincoln Nebraska. In general, there are two tests, one for dust and one for water. Aaron Steggs, Senior Test Engineer with NCEE explains, “The testing to receive the dust rating is not trivial. There is a vacuum test on the enclosure to ensure that no ingress of dust can occur. The vacuum pressure used is 2kPa.”

Aaron goes on to explain a little about the water test, “When talking about immersion testing, there is a greater chance of water being forced into any opening due to the weight of the water about the instrument under test.”

In any case, we have passed both the dust and water test and now you can have the accuracy and fast response of the Digital 300 Series in an IP rated enclosure.

For more info about our digital 200 mass flow meters and controllers, please visit www.teledyne-hi.com or click the button below for more inforamation on the IP-67 version now available.

Interested in additional  information on the IP-67


Tags: mass flow instruments, IP-67

How monitoring instrumentation is helping preserve the Emancipation Proclamation

Posted by Doug Baker on Tue, Mar 06, 2018 @ 03:53 PM

Emancipation Proclamation Blog.jpgFebruary is the month when citizens in the United States celebrate the history and culture of African-Americans. In early Feburary, scientists from the Pressure & Vacuum Group at NIST (National Institute of Standards & Technology) installed a special case designed to hold President Abraham Lincoln’s first handwritten draft of the Emancipation Proclamation and 13th Amendment in the Smithsonian’s National Museum of African American History & Culture. You can watch a video of the installation here:



The Emancipation Proclamation freed slaves in the Confederate States in 1863. After the Proclamation, the American Civil War becomes more about the struggle for freedom. In turn, Emancipation becomes law for the entire United States via the 13th Amendment to the US Constitution.

The priceless handwritten draft is now stored in in a sealed case with monitoring instrumentation. According to an article posted on the NIST website (https://www.nist.gov/news-events/news/2017/04/making-airtight-case-freedom ), the system tracks pressure, temperature, relative humidity, and oxygen content. The NIST article also says that the system uses 4% oxygen to help maintain the color of the iron gall ink.

Emancipation Oak Tree.pngNow, another interesting thing we can celebrate about the Emancipation Proclamation is the famous Emancipation Oak. Located on the campus of Hampton University, in Hampton Virginia. Note that Hampton is also the home of Teledyne Hastings. The Emancipation Oak was the site of the first reading of the Proclamation in the South according to the Hampton University Website (http://www.hamptonu.edu/about/emancipation_oak.cfm ). The tree has a diameter of over 100 feet and the oak has been designated as one of the 10 Great Trees of the World by the National Geographic Society.

For information on Teledyne Hastings and our Mass Flow Meters and Controllers or Vacuum Gauges, please visit www.teledyne-hi.com or click the button below

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Tags: General Interest

John Glenn, NASA Langley, and Hampton, VA

Posted by Doug Baker on Mon, Dec 12, 2016 @ 04:22 PM

As we say good-bye to John Glenn, it is a good time for Teledyne Hastings to recall with pride our company’s and our city’s connection to this great American hero. Now, many people know that John Glenn was the first American to orbit the earth. But most people don’t know that the original seven Mercury astronauts, including John Glenn, received their original spaceflight training in 1959 at NASA-Langley in Hampton Virginia which is also our home for Teledyne Hastings.


The Hampton Roads area of Virginia has memorialized several landmarks to commemorate Project Mercury. There are several bridges in the city of Hampton which are named for the astronauts. “Military Highway” was renamed to Mercury Boulevard. And, in Newport News, the Denbigh branch of the Newport News Public Library System is the “Grissom Library”.   

NASA was formed in late 1958 when NACA operations were converted over. Previously, NACA (National Advisory Committee for Aeronautics) was established in 1915 and built Langley field in Hampton. Now in doing some background reading for this blog, I found it interesting to learn that NACA was created out of fear that the U.S.A. might be falling behind the Europeans in aeronautics and that NASA, in turn, was created out of fear that the U.S.A. was falling behind the Soviets in the Space Race.


In a book entitled The Story of Hastings-Raydist, Carol Saunders points out that NACA did not hire many engineers during the first part of the Great Depression. But, in 1935, NACA accelerated hiring and they brought on Charles Hastings as a “Junior Scientific Aide”. In 1939, a newly hired mathematician named Mary Comstock was hired and placed in an office across the hall. The two were married and together created Hastings Instruments in 1944.


And speaking of mathematicians at Langley, there is a movie “Hidden Figures” (released December 25, 2016), which tells the story of three female mathematicians who were part of the computer pool. Which brings us back to John Glenn. In the early days of computers, engineers did not always trust the results of the electronic data processors. The computer pool, in other words, human mathematicians, were used to crunch through complex calculations. Before his historic flight in 1962, Glenn requested that one of these computer pool women, Katherine Johnson, verify the results of the computer. The contributions of these women to the space program was remarkable.

For more information on Teledyne Hastings Instruments click the button below or visit www.teledynehastings.com

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The following books were referenced in the writing of this blog:

Hidden Figures by Margot Lee Shetterly

Hampton - From the Sea to the Stars edited by James T. Stensvaag

The Story of Hastings-Raydist by Carol Hastings Saunders  

Tags: NASA

300 Vue - Inputs and Outputs

Posted by Doug Baker on Thu, Nov 17, 2016 @ 08:52 AM

Vue_Touch_Screen.jpgTeledyne Hastings is proud to release our newest, most advanced, line of digital flow meters and flow controllers - the 300 Vue. In this blog, we will discuss the three types of Input/Output (I/O) that can be used with the 300 Vue. These are: Analog, Digital, and Touchscreen Display.


(1)   Analog

The 300 Vue is very flexible. The instrument can be configured to give and receive analog signals. For example, the 300 Vue can use 0-5 VDC, 0-10 VDC, 4-20 mA, or 0-20 mA.

Let’s take a look at a 300 Vue flow controller which has been setup to have a full scale flow rate of 100 sccm and has 0-5 VDC I/O. In the case of a flow controller, there are two analog voltage signals that we need to understand. The first is the flow output signal. In our example (0-5 VDC), 5 VDC corresponds to 100% of the full scale of the flow controller. The relationship between the voltage output signal and flow rate is linear. So, if we have an output of 1 VDC from the 300 Vue, then we would have a flow rate of 20% of full scale which corresponds to 20 sccm (20% * 100 sccm = 20 sccm).

Correspondingly, in our example, the 300 Vue will accept an analog command signal between 0 and 5 VDC. Again, 5VDC corresponds to 100% command signal. The command signal tells the flow controller how to set the flow rate. So, if we wanted the flow rate to be 75 sccm, we would provide a 3.75 VDC command voltage  (75 sccm* (5 VDC/100 SCCM) = 3.75 VDC).

One last comment before we move on. Analog I/O is still used in many applications. Older flow power supplies and PLC’s often utilize analog I/O. The 300 Vue flow instrument makes it easy to integrate into these systems.

Interested in more information on the Vue? click here

(2)      Digital

The 300 Vue can provide digital I/O via RS232 or RS485. Connection to the digital port is made via the micro USB connector or the small bayonet-style connector. Let’s take a quick look at an RS232 command for the 300 Vue. If we send “F”, the 300 Vue will respond with the flow rate.

f <cr> <lf>

25.889 sccm


Simple - right? Now in the case of a flow controller, we will want to be able to send a command signal to tell the flow controller how to set the flow rate. One way to do this is to use V5, the “Setpoint”. The Setpoint Command is simply the flow rate expressed as a percent of the flow controller’s full scale. So, “V5=100” will set the flow rate to 100% of full scale. You can also use V4 which sends the command in the given units, as opposed to % of full scale.

Digital communication with the 300 Vue can be utilized in a few different ways. First, you can use our free user software which can be obtained from our website. If you want to see all of the capability (including flow data logging) you can watch this short “How To” video.

Next, many of our digital flow controller users write their own code using LabView. By working with the “F” and the “V5=  “, or “V4=  “ commands, the user can easily read and control the flow rate in their application.

Here at Teledyne, we often use TeraTerm for communicating with our digital flow instruments. Click to visit TeraTerm website for more information.   

TeraTerm is nice because it is open source (free) yet it is very powerful. I also like the fact that TeraTerm allows the user to save and restore a communication set up file. In other words, once you have a TeraTerm “ini” file working, you can save it so that you don’t have to reconfigure the settings each time you start up the program. If you have TeraTerm and would like a copy of my setup file for the 300 Vue, just send me an email

Interested in more information on the Vue? click here

(3)      Touchscreen Display

Ok, we’ve talked a little bit about analog I/O and digital communications. Now, let’s explore the coolest feature of the 300 Vue – the color touchscreen display. With the touchscreen display, it is very easy to see and control the flow rate. First, we should point out that the 300 Vue flow instrument is very easy to power up; you just plug in the connector and you are in control.

Top View with Plug.jpg 

Once the flow instrument is powered, the flow rate is observed as shown in the picture below:


Now, to change the flow setpoint or command signal we touch Setpoint and we see the numeric keypad screen as shown below.


Changing the setpoint is easy… you just type the value you want and hit ENTER. The display then returns to showing the flow rate.


The 300 Vue is very flexible with respect to Inputs and Outputs. If you have questions about I/O, our applications engineers are always standing by and ready to help. You can reach us at hastings_instruments@teledyne.com or by calling 1-800-950-2468.

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Tags: Digital Flow Meter, Flow Controller, 300 Vue