KROHNE SMARTPAT Process Analytics Sensors

The KROHNE SMARTPAT is a series of digital 2-wire loop powered sensors with integrated transmitter technology. Using a VP cable, any SMARTPAT sensor can be connected directly to the process control system via 4-20 mA / HART 7 interface, which provides a large advantages in both handling and costs of a measuring point. Available in pH, ORP, Conductivity, Total Suspended Solids, Oxygen, Disinfectant, and Turbidity. Additional transmitters on site are no longer necessary. All SMARTPAT sensors can be configured and calibrated offline via PACTware FDT/DTM, on site with a HART handheld, or an optional loop powered operating unit.

Instrument Specialties, Inc.
http://isi.group
407-324-7800

Continuous In-Line Measurement of Process Liquid Viscosity

In-line process viscosity measurement system.
Image courtesy Krohne, Inc.

Among the many analytical instruments from Krohne is the Viscoline process viscosity measurement system. It provides continuous in-line measurement of process liquid viscosity.

Krohne describes the operating principle...

The fluid flows through a continuous pipe containing two low pressure drop static mixers. The sensor device measures the pressure drop at both static mixers by means of two differential pressure measurements: ΔP1 and ΔP2. Precise pipe flow rate measurement is obtained from the integrated KROHNE OPTIMASS 7000 straight tube Coriolis meter which is uniquely insensitive to fluid viscosity effects. From the two pressure drop measurements and the flow rat reading, the fluid flow parameters are processed in the system, and the pipeline viscosity is determined. A temperature reading can be useful for thermal correction when a reference measurement is required. Such correction requires laboratory thermal characterization or dual measurement.

For solutions to your process measurement and control challenges, share them with an instrumentation specialist. Leverage your own process knowledge and experience with their product application expertise.

In-Line Process Viscosity Measurement from Instrument Specialties, Inc.

Ultrasonic Flow Measurement Overview

One of several versions of ultrasonic flowmeter suitable
for custody transfer operations.
Courtesy Krohne

Ultrasonic flow meters measure, via sound waves inaudible to humans, the velocity of fluid flowing through a conduit. The conduit can be a recognizable closed piping run, or open channels, flumes, or chutes. The technology is predominantly applied to liquids and gases. 

There are three types of ultrasonic flow meters, differentiated by their means of measurement. An open channel flow meter derives liquid depth by computing geometrical distance, combining it with a velocity measurement and known dimensional properties of a flume or other channel. A Doppler shift flow meter reflects ultrasonic energy off sonically reflective materials and measures the frequency shift between emission and reflection to derive a fluid velocity measurement. The contrapropogating transit-time flow meter, more recognizably, the transmission flow meter. The transmission flow meter has two versions: the in-line and the clamp-on. The in-line configuration is intrusive, with flow meter hardware extending into and exposed to the measured media. A clamp-on style ultrasonic flow meter resides on the outside of the pipe, emitting and receiving the ultrasonic pulses through the pipe wall. These process measurement tools, using ultrasound technology, have the ability to measure fluid velocity and calculate volumetric, mass, and totalized flow. The use of ultrasonic flow measurement is prevalent in the oil and gas, nuclear, wastewater, pharmaceutical, and food and beverage industries. It is also employed in energy management systems as a means to measure energy demand. 

For intrusive flow meters, sensors are fitted opposite one another and alternate bouncing ultrasonic signals back and forth in the pipe, in an almost tennis-like format. In an elementary explanation, by increasing the number of sensors, engineers are able to decipher flow proportions through calculations of velocity between sensory transmissions; thereby, the flow volume can be computed. 

For externally mounted flow meters, a clamp-on device affixes the flow meter measurement elements to the pipe. One special characteristic of clamp-on flow meters is the ability to transmit ultrasonic signals through piping up to four meters in diameter, making them suitable for application in very large systems such as those found in hydroelectric or wastewater installations. The clamp-on arrangement also facilitates addition of a flow measurement point to an existing system without process interruption. 

The technology is pervasive in the processing industries, having its particular niche of applications where it excels. Proper installation is a key element in producing reliable and consistent results. Ultrasonic energy flow technology is used for custody transfer of natural gases and petroleum liquids. Custody transfer usually entails following industry, national, and government standards and regulations. Other popular applications include compressed air system monitoring and energy usage metering. 

Ultrasonic flow meters, with no moving parts, are comparatively low maintenance and self-diagnosing. Temperature and pressure measurements are needed to calculate mass flow of gases. When measuring liquid mass flow in pipes, it is generally necessary for the pipe cross section to be media filled in order to obtain reliable results. 

Whatever your flow measurement challenge, share it with a process measurement specialist. Combine your process knowledge with their product application expertise to develop effective solutions.

Summary of Technologies Used For Continuous Liquid Level Measurement in Industrial Process Control

Two versions of radar level transmitters
Courtesy Krohne

Automated liquid processing operations in many fields have requirements for accurate and reliable level measurement. The variety of media and application criteria demand continuous improvement in the technology, while still retaining niches for older style units utilizing methods that, through their years of reliable service, inspire confidence in operators.

Here is a synopsis of the available technologies for instruments providing continuous liquid level measurement. All are generally available in the form of transmitters with 4-20 mA output signals, and most are provided with additional outputs and communications. What is notably not covered here are level switches or level gauges that do not deliver a continuous output signal corresponding to liquid level.

Whether considering a new installation or upgrading an existing one, it can be a good exercise to review several technologies as possible candidates for a project. None of the technologies would likely be considered the best choice for all applications. Evaluating and selecting the best fit for a project can be facilitated by reaching out to a product application specialist, sharing your applications challenges and combining your process knowledge with their product expertise to develop an effective solution.

Displacer – A displacer is essentially a float and a spring that are characterized for a particular liquid and range of surface level movement. The displacer moves in response to liquid level, changing the location of a core connected to the displacer by a stem. The core is within a linear variable differential transformer. The electrical output of the transformer changes as the core moves.

Guided Wave Radar – A radar based technology that uses a waveguide extending into the liquid. The radar signal travels through the waveguide, basically a tube. The liquid surface level creates a dielectric condition that generates a reflection. Calculations and processing of the emitted and returned signals provide a measure of distance to the liquid surface. No moving parts.

Magnetostrictive – A method employing measurement of the transit time of an electric pulse along a wire extending down an enclosed tube oriented vertically in the media. A magnetic float on the exterior of the tube moves with the liquid surface. The float’s magnetic field produces the return signal to the sensor. Processing the time from emission to return provides a measure of distance to the liquid surface.

Pulse Burst Radar - A radar based technology employing emissions in precisely timed bursts. The emission is reflectex from the liquid surface and transit time from emission to return is used to determine distance to media surface.  Not adversely impacted by changes in media conductivity, density, pressure, temperature. No moving parts.

Frequency Modulated Continuous Wave Radar – Another radar based technology that employs a radar signal that sweeps linearly across a range of frequencies. Signal processing determines distance to media surface.  Not adversely impacted by changes in media conductivity, density, pressure, temperature. No moving parts.

RF Capacitance - As media rises and falls in the tank, the amount of capacitance developed between the sensing probe and the ground reference (usually the side metal sidewall) also rises and falls. This change in capacitance is converted into a proportional 4-20 mA output signal. Requires contact between the media and the sensor, as well as a good ground reference. No moving parts.

Ultrasonic Non-Contact – Ultrasonic emission from above the liquid is reflected off the surface. The transit time between emission and return are used to calculate the distance to the liquid surface. No contact with media and no moving parts.

Differential Pressure – Pressure sensor at the bottom of a vessel measures the pressure developed by the height of the liquid in the tank. No moving parts. A variation of this method is often called a bubbler, which essentially measures hydrostatic pressure exerted on  the gas in a tube extending into the contained liquid. It has the advantage of avoiding contact between the measuring instrument parts, with the exception of the dip tube, and the subject liquid.

Laser - Probably one of the latest arrivals on the liquid level measurement scene, laser emission and return detection is used with time interval measuring to accurately determine the distance from the sensor source to the liquid surface.

Load Cell - A load cell or strain gauge can be incorporated into the support structure of the liquid containing vessel. Changes in the liquid level in the vessel are detected as distortions to the structure and converted, using tank geometry and specific gravity of the liquid.

All of these technologies have their own set of attributes which may make them more suitable to a particular range of applications. Consulting with a product specialist will help determine which technologies are the best fit for your application.

Video Shows How to Install a Portable Ultrasonic Clamp-on Flowmeter

Krohne Optisonic 6300 P
Portable Ultrasonic Flowmeter

Ultrasonic flowmeters, being capable of operating from outside a pipe, are well suited to field measurements and other portable applications in industrial process measurement. Krohne, a globally recognized manufacturer of flow, pressure, temperature, level, and other instruments for process measurement and control, has produced video instructions for field installation and operation of their portable ultrasonic clamp-on flowmeter. The video is included below. Though the presentation is based upon the Krohne product, there is good general knowledge about portable ultrasonic flowmeters to be had from the video.

Watch the video and build your knowledge. Share your process measurement challenges with application specialists, combining your process knowledge with their product application expertise to formulate effective solutions.

Turbidity Meter - Hygienic for Food and Beverage Industry

Hygienic Turbidity Measurement Instrument
Krohne

Turbidity is a measurement related to the particle content of a fluid. While it does not provide a direct particle count, it does deliver an indication of the optical clarity of the liquid, with the measurement being proportional to particle content. This is important to food and beverage manufacturers in maintaining consistent levels of quality and product character.

A liquid processing industry, such as the food and beverage industry, can benefit from continuous monitoring of turbidity, as opposed to periodic sampling. The rate at which manufacturers process liquids generally negates the use of a sampling method due to the large amounts of material processed between sampling and the processing of their results. Continuous measurement provides the fastest response to any trending or immediate changes in the fluid character.

One instrument manufacturer, Krohne, provides hygienic turbidity meters that can be installed, inserted into a pipe or vessel, to provide continuous turbidity readings. The instrument utilizes a near infrared light source, which eliminates the impact of medium color on the measurement. Krohne delivers a measuring system for monitoring the optical density of absorption of fluids in order to monitor continuous process results or to securely indicate changes. The process instrument has the capability to calibrate itself, preserving its high level of accuracy. Analog and digital outputs provide connective pathways to monitoring and control systems, and a number of product variants accommodate ease of use and several measurement ranges.

More detail is provided below in the technical data sheet. Share you process instrumentation requirements and challenges with product application specialists, combining your process knowledge and experience with their product application expertise to develop effective solutions.

Hygienic Turbidity Meter for Food and Beverage Industry from Instrument Specialties, Inc.

Fundamentals of Radar Technology for Level Gauging

RADAR Level transmitter
courtesy of KROHNE

The term “radar” is generally understood to mean a method by means of which short electromagnetic waves are used to detect distant objects and determine their location and movement. The term RADAR is an acronym from “RAdio Detection And Ranging”.

A complete radar measuring system is comprised of a transmitter with antenna, a transmission path, the reflecting target, a further transmission path (usually identical with the first one), and a receiver with antenna. Two separate antennas may be used, but often just one is used for both transmitting and receiving the radar signal.

Measuring the level of liquids or solids in vessels is a frequent requirement in industry. RADAR level measurement is the use of a radar signal is emitted via an antenna, reflected from the surface of the product and the echo received again after a time interval “t”.

The document below, courtesy of KROHNE, is an excellent technical reference for a strong understanding of RADAR level measurement.

Fundamentals of Radar Technology for Level Gauging from Instrument Specialties, Inc.

Detecting Free Fatty Acids, Polar Material, Peroxide and Dirt in Edible Oil and Fat Applications

Detection of FFA, TPM, POV, moisture or dirt
with the new Krohne analyzer

Instantaneous detection of FFA, TPM, POV moisture or dirt in edible oil and fat application is now possible with the use of a new inline continuous analyzer from the manufacturer Krohne. The OPTIQUAD-EOF 4050 W "peeks" inside the process through an optical window placed in a standard measuring section. Four standard 4-20 mA control outputs are provided for process control. Additionally,  the measurement of anisidine value (AV) and iodine value (IV) are possible (application dependent). 

Detection of these variables have traditionally been done using conventional laboratory methods. The new inline analyzer reduces the need for sampling and the associated transport and handling which raise the probability of errors and increases cost.

The optical spectroscopy analyzing method allows for a wide range of use in edible oil applications, such as oil extraction, oil refinement and frying processes up to oil recycling, as well as fat processing. For example, the continuous inline measurement of FFA content in frying oil helps to minimize the addition of fresh oil: the FFA value can be kept below a defined limit while allowing to maintain a high level of quality. 

The spectroscopic analysis system consists of the analyzer unit and the operating unit, both rated IP65/NEMA4X. The operating unit is an industrial PC with touch screen display. It uses up to four measuring methods (transmission, scattering, fluorescence and refraction) with up to 12 wavelengths from ultraviolet to infrared. The underlying calibration is calculated automatically from reference data specific to the application.

For more information about this or any Krohne product, contact:

Instrument Specialties Inc.
3885 St. Johns Parkway
Sanford, FL 32771
phone 407.324.7800
fax 407.324.1104

www.isisales.com

Concepts of Process Instrument Calibration

Volumetric calibration rig

Measuring devices are an integral part of our lives nowadays, whether in everyday life or on the job. Take, for example, the scales at the supermarket check-out, the fuel volume measurement at the filling station pump, temperature measurement, velocity, flow volume and thermal energy, taxi meters etc. The wide variety of available quantities to be measured and measuring devices clearly illustrates the complex interplay between the quantity to be measured and the measuring device used. What does "accurate" actually mean in this context and how is this accuracy demonstrated? Why do we need accurate measuring devices?

Using the example of flowmeters, the following document will go into detail about these and other aspects of calibration and accuracy, and also looks at calibration standards from different countries around the world.

Concepts of Process Instrument Calibration from Instrument Specialties, Inc.

For more information regarding process instrumentation and calibration, contact:

Instrument Specialties Inc.
3885 St. Johns Parkway
Sanford, FL 32771
phone 407.324.7800
fax 407.324.1104
www.isisales.com

Spectroscopic Analysis Systems for Continuous Inline Measurement

1) Analyzer Unit, 2) Optical window
3) Medium (e.g. milk)

Light of varying wavelengths is coupled into the medium using LEDs and laser diodes, which in turn measures various contents of a product, such as protein, fat, free fatty acids, lactose and the COD value. All while still inline (in the pipeline during the process), with the utmost precision. The values of up to four different optical effects are calculated and converted to highly accurate measurements.

Wave Matrix - Four Optical Analytical Principles

The analyzer uses several light sources and works in the UV, VIS, NIR and IR spectral ranges. The light waves are coupled into the medium via an optical window and measured using appropriate sensor elements, depending on the analytical process.

The analyzer uses four measuring principles to synchronously measure the transmission, scattering, fluorescence and refraction values of the light. Depending on the application, the analyzer works synchronously with a combination of up to 12 different wavelengths of between 200 and 4000 nm. The multitude of raw measured values are fed into a mathematical


model which determines, for example, the protein and fat content.

Accuracy and Repeatability

Thanks to the elimination of moving parts, the measuring velocity,  long-term accuracy and repeatability were significantly improved upon compared to typical bypass devices. In addition, compared to laboratory measurements, using the analyzer eliminates potential error sources that may be caused by the taking, transporting and preparation of samples.

Hygienic process connection

The analyzer is connected to the process without contact via an optical window in an easy to clean via (SIP/CIP) and FDA-compliant standard housing.


Water Cooling and Air Flushing

Integrated water cooling is recommended to ensure optimal cooling at higher ambient temperatures and when measuring hot media. Air flushing effectively prevents condensation on the optical window at low process temperatures.

Recalibration and Maintenance

Compared to typical laboratory and bypass devices, no daily recalibrations are necessary when operating the analyzer. As there are no moving parts, high long-term stability and thus minimal maintenance is achieved.

If, however, it does prove necessary to check a reading, this can be done easily with the integrated sampling valve and by entering reference values determined in the laboratory directly into the analyzer.

Compact and Flexible

The compact operating unit of the analyzer is very flexible and can be installed anywhere thanks to a serial interface - either in its own stainless steel housing or into a control cabinet on site. The measured values and status information can be read off this unit and sent to the automation system.

For more information, visit OPTIQUAD at Instrument Specialties