Basics of Thermocouple Junction Design

Industrial thermocouples
Industrial thermocouples (AST)
Thermocouples are simple devices made up of several key components: thermocouple wire, electrical insulation, and the sensing junction. Many thermocouple designs also include a stainless steel sheath that protects the thermocouple from vibration, shock, and corrosion.

A thermocouple has three variations of sensing tip (or junction):
  • Exposed junction, where the exposed wire tips and welded bead have no covering or protection.
  • Grounded junction, where the welded bead is in physical contact with the thermocouple's sheath.
  • Ungrounded junction, where the tip is inside the thermocouple sheath, but is electrical (and somewhat thermally) insulated from the sheath (no sheath contact).
Exposed junction thermocouples respond to temperature change quickly and are less costly, but their signals are susceptible erratic reading caused by induced or conducted electrical noise. Because there is no sheath, they are also prone to mechanical damage and ambient contamination.

Grounded junction thermocouples provide fast response and are mechanically more robust, with a metallic sheath that protects the thermocouple both mechanically and from contaminants. But because their sensing tip is in contact with the external sheath, their signal still can be affected by externally induced or conducted electrical noise.

Ungrounded thermocouples, like grounded, are protected mechanically and from ambient contaminants by their sheath. However, their sensing junctions are kept separate from their metallic sheath, isolating the junction from external electrical  interference. This separation does come at a small cost in temperature sensing responsiveness though.

For safety, precision, and optimum performance, always talk to an applications specialist when applying temperature sensors. A short phone call can prevent major headaches and lost time in  troubleshooting a misapplied thermocouple.

Ives Equipment: Growth and Leadership in Automation and Control

For over 60 years, Ives Equipment Corporation has successfully served the industries of eastern and central Pennsylvania, Delaware, Maryland, New Jersey, metro NY, and Virginia with the latest in process control equipment and services. Our business has been built on a foundation of quality people, highly trained and experienced, who take a keen interest in finding the optimum solutions to our customers' control problems.

Accurate Low-Flow Measurement and High-speed Communication in Supercritical Fluid Extraction and Chromatography Systems

Low-Flow Measurement in Supercritical Fluid Extraction
Low-Flow Measurement in Supercritical Fluid Extraction
A food producer removes caffeine from coffee beans to create a decaffeinated version of its most popular blend. A manufacturer of dietary supplements extracts pesticides and organic solvents from ginseng to ensure a higher-quality end product. A crime laboratory measures the amount of morphine in a blood sample to analyze the usage habits of a drug addict.

These scenarios might not appear to share much in common – after all, what does your favorite morning beverage have to do with forensic drug testing? – but there are important similarities. In each example, a supercritical fluid can be used to carry out precise, efficient, low-toxicity chemical extraction or chromatography.

SITRANS F C MASS 2100  SITRANS FCT010
SITRANS F C MASS 2100
sensor paired with the
SITRANS FCT010
digital transmitter
Regardless of the industry or application, supercritical fluid extraction (SFE) and super- critical fluid chromatography (SFC) require a very specific set of operating conditions. Keeping the environment just right for SFE and SFC requires consistently accurate process measurements – all of which are made possible by incorporating a high-performance Coriolis mass flowmeter designed to measure accurately at low flow rates.

Download this Application Note Here

The Application

An analytical science corporation in the northeastern USA develops instruments for laboratory-based applications across a broad range of industrial, academic and government organizations. Among their specialties are SFE and SFC systems tailored to the specific needs of customers and designed to extract and/or measure a variety of chemical compounds.

Their systems rely on supercritical carbon dioxide (CO2) instead of organic solvents to provide selective sample extractions and/or measurement. CO2 normally behaves as a gas at standard temperature and pressure, or as dry ice when frozen. But when CO2 is held at or above its critical temperature of 31.2 °C (87.8 °F) and critical pressure of 73.8 bar (1071.6 psi), it achieves a super- critical state midway between a gas and a liquid, with liquid-like density and solvating power but a viscosity near zero. Using supercritical CO2 results in shorter completion times and purer extracts – not to mention lower operating costs in comparison to solvent-based systems.

To kick off SFE or SFC, supercritical CO2 is pumped into the system and passes through an integrated Coriolis flowmeter, which measures the incoming mass flow rate, density and temperature. This is a crucial step in both processes, as it’s the prima- ry way to ensure that all CO2 flowing into the system remains in the desired fluid state. Once conditions are verified by the flowmeter, the CO2 helps to extract the compounds (in SFE) or separate and measure them (in SFC).

The Challenge

For more than 15 years, the company has had the option to add a SITRANS F C Coriolis flowmeter from Siemens to their SFE and SFC systems, depending on customer requirements. Their meter of choice consisted of a MASS 2100 sensor in size DI 1.5 (1/16”) and a MASS 6000 transmitter. They initially selected the Siemens solution because of its capability for very accurate measurement – as high as 0.1% of flow rate – under the low-flow conditions required for chemical extraction and measurement with supercritical CO2. The robust construction of the MASS 2100 sensor also offered the reassurance of long-term durability, even in high-pressure environments.

Over time, the company recognized the need to expand into a broader market- place by ensuring that all of their super- critical fluid solutions complied with the RoHS Directive for hazardous materials, which would open the opportunity to sell into the European Union. Having come to appreciate the reliability of the SITRANS F C product line and the responsiveness of Siemens customer support, they turned to Siemens for a digitally based, RoHS-compliant Coriolis flow alternative. That’s when they were introduced to the SITRANS FCT010.

The Solution

Part of the next-generation digital flow platform from Siemens, the FCT010 is a powerful, very compact Coriolis transmitter designed especially for skids and other small-footprint assemblies – a major benefit for the SFE and SFC systems given their limited availability of space.

Another prerequisite for selection was superior performance, and the FCT010 does not disappoint. The transmitter measures with advanced digital signal processing technology, so it produces a stronger signal-to-noise ratio than an analog transmitter for higher accuracy, improved resistance to process noise and a more stable zero point. The FCT010 can also detect and respond to even the smallest changes in flow with a best-in-class 100 Hz update rate.

The company was pleased to learn that the new transmitter could be paired seamlessly with the existing MASS 2100 sensor, which over the course of 15 years has proven to be the ideal low-flow sensor for measuring supercritical CO2. They also liked that the FCT010 is extremely simple to install as a result of its small size and easy-to-use wiring connections.

Ultimately, they placed an order for 100 FCT010 transmitters to be included with new SFE and SFC systems. Now that the enhanced Coriolis flow solutions are in place, the upgraded systems are benefit- ting from faster communication coupled with better process data – all of which adds up to higher-precision, more effi- cient extractions and measurements for laboratories.

With help from the digitally powered SITRANS F C Coriolis flow family, the corporation is equipping manufacturers and researchers with advanced tools that optimize science, commerce and their bottom lines.

For more information, call Ives Equipment at (877) 768-1600 or visit https://ivesequipment.com.

Reprinted with permission from Siemens.

Expertly Applying Process Control Instrumentation, Valves, and Process Equipment for Over 60 Years

Ives Equipment, founded in 1954, provides a diverse range of process control equipment, including valves, regulators, wireless products, flow products, pressure gauges, control products, level instrumentation, sanitary products, temperature instruments, analytical products, electric heat trace and bio-pharmaceutical products.


Explosion-Proof ASIC or HART Pressure Transmitter

UE TX200
UE TX200
The TX200 is a compact, rugged pressure transmitter utilizing ASIC technology to provide optimum sensor signal conditioning and temperature compensation of the sensor output. It is designed for process control industries worldwide and ideally suited for petrochemical and upstream oil and gas applications. The TX200 provides a cost-effective solution to using conventional process transmitters.

The  fixed range model TX200B is recommended for use where process pressure is consistent within the range and where physical access to the transmitter is limited or not required.

The field adjustable model TX200A allows access to zero and span the transmitter. The transmitter may be spanned up to 5:1 and for ease of calibration, does not require a calibrated pressure source and can be calibrated in-place.

Both TX200 models feature an all welded, 316 stainless steel hermetically sealed enclosure providing airtight and watertight protection within the harshest environments. A 316 stainless steel, rotatable cover protects product markings and adjustment buttons (TX200A) from the elements and tampering. The TX200 lends itself to control panel mounting or direct process mounting due to its light-weight, cylindrical design.

TX200H Hart Models

The TX200H is a HART Smart pressure transmitter that provides simplified  eld adjustment while reliably communicating asset management data utilizing the latest HART 7 specification. A proprietary calibration process insures optimum temperature compensation limiting thermal effects on the sensor output. As with the ASIC TX200, it is suited for process control industries worldwide and provides a cost-effective solution to using conventional HART transmitters.

Download the PDF cut sheet for the UE TX200 from this link or read the embedded document below.

For more information on United Electric Controls products, contact Ives Equipment by calling (877) 768-1600 or by visiting https://ivesequipment.com.

What Are Turbine Flow Meters?

Turbine Flow Meter
Turbine Flow Meter (Niagara WPX)
Turbine flow meters are process instruments used in a variety of industrial applications to measure the flow of a fluids. These types of flow meters operate under the simple principle that the rotation of the turbine will be constant as the turbine is acted upon by a fluid passing through the flow meter.

Turbine flow meters use the mechanical energy of the fluid to rotate a turbine blade in the flow stream and provide precise and accurate flow measurement. The flow impinging upon the turbine blades causes the rotor to spin. The angular velocity of a turbine flow meter is proportional to flow rate. The rotational velocity of the turbine is interpreted as an electrical frequency output through the use of magnetic pick-ups. As each turbine blade passes by the magnetic pick-up coil, a voltage pulse is generated which is a measure of the flow rate. The total number of pulses gives a measure of the total flow which can be totalized with a maximum error of a single pulse.

The relationship of the angle of the turbine meter blades to the flow stream governs the angular velocity and the output frequency of the meter. The sharper the angle of the turbine blade, the higher the frequency output.

Easy to maintain while also boasting reliability, turbine flow meters are known to be cost-effective solutions that make an ideal device for measuring flow rate. Aside from excellent rangeability, they also provide high response rate and high accuracy compared to other available types of flow meters. Turbine flow meters are sturdy, need very little maintenance, and seldom exhibit much deviation in performance.

These meters are used in multiple industries to reliably measure the velocity of a variety of liquids, gases and vapors over a very broad range of flow rates, temperatures, and viscosities. Turbine flow meters are used to provide measurement information in crude oil production, chemical processing, blending systems, tank storage, product off-loading, product loading, and many other applications across many industries.

Advantages
  • Simple and durable structure
  • Easy to install and maintain
  • Low pressure drop
  • Operate best in applications with fast, steadyflows
  • Operate under a wide range of temperatures and pressures
Disadvantages
  • Require straight run of pipe upstream and downstream
  • Need constant back-pressure
  • Best for lower fluid viscosity
  • Bubbles in liquids affect accuracy
  • Bearing wear
(877) 768-1600

An Exceptional Clamp- on Ultrasonic Flow Measurement Solution for Any Liquid Process

SITRANS FS230 flow system
The SITRANS FS230 digital clamp-on ultrasonic flowmeter is a process-optimizing solution for measuring flow in virtually any liquid application. Designed to provide both exceptional performance and outstanding cost savings, the FS230 is an ideal fit for many industries requiring high-quality liquid flow measurement – including water and wastewater, HVAC and power, food and beverage, pharmaceutical, chemical, mining and pulp and paper.

The SITRANS FS230 flow system consists of a SITRANS FST030 transmitter paired with SITRANS FSS200 clamp-on ultrasonic sensors, which are available in three different models: WideBeam® (High-Precision), Universal and High-Temperature.

Download the PDF from the Ives Equipment web site here, or read the document embedded below.

For more information, contact Ives by calling 877-768-1600 or by visiting https://ivesequipment.com.