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.

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.

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.

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

The 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.
Teledyne Hastings is proud to announce our newest 4-channel power supply, controller and display, the
The addition of Ethernet communication provides access to the newest feature that the THCD-401 has to offer; the internal web server! The web server can be accessed by entering the IP address of the THCD-401 into a browser’s address bar (requires static IP address configuration on the network prior to use). While the web server feature works best in Mozilla™ Firefox®, it can be accessed via any browser you choose. Figure 2 shows the web server interface with applications along the top navigation bar and a live data stream for remote read.

The early part of the 1950’s was prosperous for Hastings due in part to the demand for the Raydist and large military contracts as a result of the Korean War. Sales nearly tripled between 1950 and 1953 and there were almost 200 employees. Hastings had outgrown its space yet again and expanded to a 14,000 square foot building on Newcomb Avenue (current day location for Teledyne Hastings). The building was originally used as a car barn for street cars, then as a World War I armory and eventually as a manufacturing plant for ladies clothing.
A small percentage of Hastings business during the early 1950’s was for instrument sales. The most important of these products were the air-meters, vacuum gauges, flow meters, accelerometers and an electronic standard cell. In order to grow this part of the business, Hastings decided to set up a manufacturer’s representative program. By the end of 1953, Hasting’s was looking forward to seeing this manufacturer’s representative program vastly increasing instrument sales.
By 1947, the Hastings Instrument Company could count many successful projects. Their list of products included the following:
After several sales pitches and demonstrations, Hastings received two large contracts for Raydist. Along with these two contracts, the company was busy building Air-Meters for commercial sales. Before selling the Air-Meters, the instruments needed to be calibrated. In those early days, calibration was done by driving down the road holding a probe out the window while someone in the passenger seat held the Air-Meter. When the car reached 5, 10, 15 etc… mph the passenger would make a note on the blank dial face and then return to the house where they would neatly letter the dial face.
During this period of growth, Hastings realized that it was time to find a new location for the business. By now, there were 17 people working elbow-to-elbow at the Hastings’ home and that could not continue. The company settled on temporary location in an old brick distributorship building that had a leaky roof and flooded at spring tides, but it was at the price they could afford.
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n addition to the list of commercial instruments above, Hastings developed specialized instruments for specific customers. For example: the “Ventimeter” was used by the army to measure ventilation in clothing to keep wearers comfortable under extreme weather conditions. The Hastings Company was now growing fast and generating handsome profits for its stakeholders.
Recently, 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, 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
In September 1944, the Hastings Instrument Company started to take shape. For quite some time, Charles & Mary conducted the business out of their home. They received their first order in December from the Naval Aircraft Factory in Philadelphia for $800. The order was for a rotary magnetic switch for commutating electrical circuits.
Business continued to grow. Seventeen employees would arrive at the Hastings home around 7pm on Monday, Wednesday and Friday to work on their electronic projects (see image on right). During the day, Mary would take care of miscellaneous projects. On one occasion, Mary agreed to have some Raydist cabinets painted by the time Charles came home. Unfortunately, the air compressor was out of air so Mary came up with another plan. She would take the car to the nearby service station and put as much air in the tires as she could without them bursting. She would then drive back home, attach her paint sprayer to the tires, and paint the Raydist cabinets
until her tires were almost flat. She did this several times to complete the project before Charles came home. The business activities took a toll on the Hastings home. The roof leaked and needed to be replaced from all the antennas mounted to it (see image on left), the driveway needed to be replaced from the damage of delivery trucks, Mary’s oven smelled like paint which caused some challenges when meal time came.
In January 1946, Hastings received their first order for a Raydist. The Air Material Command at Wright Field in Cleveland Ohio wanted a single-dimensional Raydist system to use during aerial photography and mapping. The final product was hand-delivered by Charles himself in October. (see image on right and below)
This 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.






We 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
Ever wonder where the idea or dream of Hastings originated? Well as part 1 of our anniversary year blog posts, we thought this would be a good place to start. Charles Hastings at the age of 10 was bitten by the radio bug and began to build and experiment with radio gear. In 1930, at the age of 16, Charles Hastings found an opportunity to fund his experiments by fixing other people’s radios. Many families had radios at this point, but they were very unreliable and frequently needed minor repairs. Charles would fix radios to earn money to buy parts for his own experiments.
Teledyne Hastings is proud to announce the release of the THCD-101 single channel power supply, controller and display. The THCD-101 can be used to operate a wide variety of mass flow meters and controllers as well as vacuum gauges and pressure transducers. The THCD-101 uses bright OLED digits which makes the display easy to view, even from a distance. The THCD-101 is extremely versatile in its configurable range and can be set up to display any unit of measurement through customizable alphanumeric characters. The power supply provides stable ±15 VDC and +24 VDC levels which can be used to operate a variety of measurement and control instruments. The display and readout features a high accuracy of ±(0.02% of Reading + 0.01% of Full Scale). The user can also set relay alarms for the control of other processes. The THCD-101 is configured at the factory to match the user’s requirements for range & units so it is ready to use right out-of-the-box.
The THCD-101 now includes digital communication via a USB ‘C’ connection or Ethernet (TCP/IP). When the power supply is connected via Ethernet, the THCD-101 provides a web server for operation and instrument configuration. The web server can be accessed by entering the IP address of the device into a browser address bar (requires static IP address configuration on the network prior to use). This allows the user control of various settings within the device and to read the devices current reading. Note that the IP Address can be changed through the menus of THCD-101. In addition to the THCD-101 web server, standalone DisplayX software can be downloaded free of charge from the Teledyne Hastings website. Should the user need to change the THCD-101’s setup, the DisplayX software or Ethernet web server is extremely helpful in streamlining this process.
As outlined above, the THCD-101 contains all the great features of the legacy THCD-100 while adding new and improved features such as USB & Ethernet digital communications and a bright OLED display. Even with these powerful additions, the instrument keeps the same 1/8 DIN size while offering a shorter depth than the previous display & readout!