NIST Traceability

Calibration means the comparison and adjustment (if necessary) of an instrument’s response to a stimulus of precisely known quantity, to ensure operational accuracy. In order to perform a calibration, one must be reasonably sure that the physical quantity used to stimulate the instrument is accurate in itself. For example, if I try calibrating a pressure gauge to read accurately at an applied pressure of 200 PSI, I must be reasonably sure that the pressure I am using to stimulate the gauge is actually 200 PSI. If it is not 200 PSI, then all I am doing is adjusting the pressure gauge to register 200 PSI when in fact it is sensing something different.

Ultimately, this is a philosophical question of epistemology: how do we know what is true? There are no easy answers here, but teams of scientists and engineers known as metrologists devote their professional lives to the study of calibration standards to ensure we have access to the best approximation of “truth” for our calibration purposes. Metrology is the science of measurement, and the central repository of expertise on this science within the United States of America is the National Institute of Standards and Technology, or the NIST (formerly known as the National Bureau of Standards, or NBS ).

Experts at the NIST work to ensure we have means of tracing measurement accuracy back to intrinsic standards, which are quantities inherently fixed (as far as anyone knows). The vibrational frequency of an isolated cesium atom when stimulated by radio energy, for example, is an intrinsic standard used for the measurement of time (forming the basis of the so-called atomic clock). So far as anyone knows, this frequency is fixed in nature and cannot vary: each and every isolated cesium atom has the exact same resonant frequency. The distance traveled in a vacuum by 1650763.73 wavelengths of light emitted by an excited krypton-86 (86Kr) atom is the intrinsic standard for one meter of length. Again, so far as anyone knows, this distance is fixed in nature and cannot vary. This means any suitably equipped laboratory in the world should be able to build their own intrinsic standards to reproduce the exact same quantities based on the same (universal) physical constants. The accuracy of an intrinsic standard is ultimately a function of nature rather than a characteristic of the device. Intrinsic standards therefore serve as absolute references which we may calibrate certain instruments against.

The machinery necessary to replicate intrinsic standards for practical use is quite expensive and usually delicate. This means the average metrologist (let alone the average industrial instrument technician) simply will never have access to one. While the concept of an intrinsic standard is tantalizing in its promise of ultimate accuracy and repeatability, it is simply beyond the reach of most laboratories to maintain.

In order for these intrinsic standards to be useful within the industrial world, we use them to calibrate other instruments, which are then used to calibrate other instruments, and so on until we arrive at the instrument we intend to calibrate for field service in a process. So long as this “chain” of instruments is calibrated against each other regularly enough to ensure good accuracy at the end-point, we may calibrate our field instruments with confidence. The documented confidence is known as NIST traceability: that the accuracy of the field instrument we calibrate is ultimately ensured by a trail of documentation leading to intrinsic standards maintained by the NIST. This “paper trail” proves to anyone interested that the accuracy of our calibrated field instruments is of the highest pedigree.

Thompson Equipment Company's calibration lab is ISO/IEC 17025 Accredited and NIST traceable.

Reprinted from "Lessons In Industrial Instrumentation" by Tony R. Kuphaldt – under the terms and conditions of the Creative Commons Attribution 4.0 International Public License.

Magnetic Flowmeters for Measuring the Frac Fluid

A piece of equipment used in hydraulic fracturing is the blender truck. It contains the equipment used to prepare and measure the "frac fluid". Frac fluid is composed of water, sand, specialty chemicals, and gels, and is highly erosive and sometimes corrosive. This "blended" mixture of sand, water and chemicals is then injected into a well to hydraulically open cracks in the rock layers below. By opening the cracks, trapped natural gas and petroleum is released and flows more freely. 

Magnetic flowmeters are employed to measure the frac fluid flow and volume.  These flowmeters must accurately meter the frac fluid into the well, stand up to the continual erosive media, and be durable enough to handle the harsh ambient conditions. Standard process magmeters experience shortened lifespans under these conditions and must be pulled from service and repaired. A better alternative is a severe service flowmeters designed specifically for this service.

Thompson Equipment Company (TECO) manufactures an electromagnetic flowmeter (magmeter) designed for frac fluid flow metering. The TECO design incorporates two significant features to improve performance and extend operating life:
  1. A ceramic sleeved liner made of “magnesia partially stabilized zirconia”
  2. The use of solid tungsten electrodes.
The TECO fracing flowmeter provides huge benefits, namely operators save money through increased uptime, they reduce health, safety and environmental risk, and reduce costs related to magmeter replacement and repair.

TECO Proudly Supports Sky High at the Midland Permian Basin Banquet & Clay Shoot

Thompson Equipment Company (TECO) proudly supports the fantastic work Sky High does "Saving Kids. Healing Families."

Sky High's mission is to provide comfort, fund research and save lives of children fighting pediatric cancer and other life-threatening conditions at Texas Children’s Cancer Center, St. Jude Children’s Research Hospital and the Ronald McDonald House of Memphis.

TECO is proud to attend and support the "Midland Permian Basin Banquet & Clay Shoot" this past September. We strongly suggest our friends, vendors, and partners get involved with this wonderful group.

Electromagnetic Flow Meters for Accurate Measurement of Flowing Conductive Fluids and Slurries

Badger Magnetic Flow Meter
Magnetic Flow Meter
(Badger Meter)
In general, magnetic flow meters are sturdy, reliable devices able to withstand hazardous environments while returning precise measurements to operators of a wide variety of processes. The magnetic flowmeter has no moving parts. Electromagnetic meters will measure virtually any conductive fluid or slurry. This includes process water and wastewater. They provide low pressure drop, high accuracy, high turndown ratio, and excellent repeatability.  It is however, necessary to fill the entire cross section of the pipe in order to derive useful volumetric flow measurements.

Electromagnetic flow meters employ Faraday’s law of electromagnetic induction, whereby voltage is induced when a conductor moves through a magnetic field. The liquid acts as the conductor, with energized coils outside the flow tube creating the magnetic field. The produced voltage is directly proportional to the flow rate. Magnetic flow meter technology is not affected by temperature, pressure, or density of the subject fluid.

Electromagnetic flow meters tend to be heavy in larger sizes and may be prohibitively expensive for some purposes. However, irrespective of price and size, there are multiple reasons why magnetic flow meters are the instrument of choice for certain applications. They are resistant to corrosion and their ability to accurately measure dirty fluids makes them very suitable for wastewater measurement. As mentioned, there are no moving parts in a magnetic flow meter, keeping maintenance to a minimum. Power requirements are also low. Electromagnetic flow meters are available in a wide range of configurations, sizes, and construction materials to accommodate various process installation

Severe service flow meter
Severe service flow meter.
Severe application magnetic flow meters provide erosion and abrasion resistant designs, capable of withstanding a variety of highly erosive applications and corrosive slurries. These special-purpose  electromagnetic flow meters utilize liners made from specialty materials like magnesia stabilized zirconia ceramic or aluminum oxide ceramic, have electrodes made of exotic metals such as Hastalloy B/C, titanium, platinum, or tungsten carbide, and include specialized coatings.

Contact Thompson Equipment Company (TECO) with any magnetic flow meter requirement. Their decades of applying, repairing, re-manufacturing, and designing magnetic flow meters will assure a successful implementation.

Choosing the Right Industrial Flow Meter

Which Industrial Flow Meter
Which Industrial Flow Meter to Choose?
Choosing the right flow measurement solution can have a major impact on operational and business performance. For this reason, companies anticipating a flow meter purchase should consult with a knowledgeable instrumentation supplier, such as Thompson Equipment Company (, in the early stages of a project. The effort spent learning about basic flow measurement techniques, and available meter options, will ensure a successful application once the equipment is installed.

This white paper, courtesy of Badger Meter, does a great job outlining all the various types of flow meter technologies, including:
  • Coriolis
  • Differential Pressure
  • Electromagnetic
  • Positive Displacement
  • Thermal Mass
  • Turbine
  • Impeller
  • Variable Area
  • Ultrasonic
  • Vortex
  • Oval Gear
  • Nutating Disc
Download your own PDF copy of "Choosing the Right Flow Meter here, or view the embedded document below.
800-528-8997 for Immediate Service

Metal Cone Variable Area Flowmeters

Metal Cone Variable Area Flowmeters
Metal Cone Variable
Area Flowmeters (ABB)
These versatile and rugged flowmeters are utilized to measuring the flow of liquids, steam and gases, particularly aggressive and opaque fluids. They are ideal for the chemical, pharmaceutical and food and beverage industries.


Metal cone variable area flowmeters are indispensable where high pressure and / or high temperature operating conditions exist. The stainless steel primaries as well as the PTFE liner primaries are proven in many applications even under hardest conditions.

Design options include:
  • Flanged connections.
  • Hygienic design.
  • PTFE-liner for aggressive fluids.
  • Steam jacket for temperature sensitive fluids.
All  metal cone variable area flowmeters are available as an analog indicator with or without alarms, as well as 4 to 20 mA electronic transmitter with HART communication, NAMUR contact outputs, and optionally with a graphical display. Metal cone variable area flowmeters can be used in all hazardous areas.

More information about metal cone variable area flowmeters can be found in the embedded document below, or you may download the ABB Variable Area Flowmeter brochure directly from this link.

Thompson Equipment Company

Impact Weighers - Principle of Operation

Impact Weigher
Impact weighers are in-line instruments used for weighing of bulk materials. They are designed to measure the force generated by the impact of flowing material on a sensing plate. This force creates a mechanical deflection as it impacts the plate. This deflection is measured by a sensor and converted into an electrical signal. That signal is then processed by an electronic controller, which displays the flow rate and total weight.

Impact Weighers

Impact weighers are designed so that the impact plate can only move horizontally. This means that from the total impact force “Fi,” only the horizontal component “Fh” is measured. In the diagram above, “Fv” is ignored. This guarantees that changes in the weight of the sensing plate, due to material build-up or sensing plate wear, will not affect the zero or accuracy of the system.

Impact Weighers
Impact Weighers components
(Thermo Scientific Ramsey)
  • Easy installation in difficult process environments 
  • Measurement is not affected by changing the impact point on the sensing plate • Build-up on the sensing plate cannot influence the zero point
  • High reliability and low maintenance 
  • Mechanical damping system absorbs shocks and damps vibration
  • Sensor allows some overload withoutdamage to the system
  • Sensor is located in a dust-tight enclosureexternal to the process stream 
  • Operates accurately in pulsating or surging flows
To learn more, download the Ramsey DE10 and DE20 Impact Weigher brochure here. For more information, contact TECO by visiting or by calling 800-528-8997.