Acoustic Wave Technology for Industrial Level Applications

acoustic wave level sensor
Acoustic wave
level sensor by
Hawk Measurement
Acoustic Wave Technology is an improved ultrasonic technic which utilizes lower frequency sound waves. Lower frequencies produce higher power and this power is further enhanced by utilizing a unique piston type transducer.

The transmission of high powered acoustic waves ensures minimal losses through the environment where the sensor is located. Due to the high powered emitted pulse, any losses have far less effect than would be experienced by traditional ultrasonic devices. More energy is transmitted hence more energy is returned. Advanced receiver circuitry is designed to identify and monitor low level return signals even when noise levels are high. The measured signal is temperature compensated to provide maximum accuracy to the outputs and display.


Level Measurement - Waste water/water:
River level, wet wells, inlet screens, tanks, sumps, pump stations, water towers, dams, basin levels, chemical storage, etc.

Level Measurement - Mining:
Crushers, surge bins, ore passes, conveyor profile, blocked chute, stockpile, stackers, reclaimers, storage silos etc.

Level Measurement - Power Stations:
Boiler bunkers, raw coal bunkers, ash pits, fly ash silos, etc.

Food, cement, plastics, grain, chemicals, paper, irrigation, quarries

The Truly Universal Approach to Gas Detection. Design, Implementation and Maintenance

Universal Gas Detection
Truly Universal Approach to Gas Detection
Reprinted with permission from an article titled

Executive Summary

Protecting your people and your physical plant, while ensuring business continuity, are the most important functions of a fixed gas detection solution. Engineering a reliable, high-performance system that makes it easier and more cost effective to meet this challenge is the driving force behind a truly universal approach to gas detection. 

This white paper is about the evolution and benefits of designing, implementing and maintaining a truly universal approach to gas detection. Our intention is to help you use this information, based on “universal truths,” to evaluate your current system and project the impact of next-generation gas detection on your organization’s safety and productivity in a global economy.


In a global economy, the challenges to personal safety, productivity, and business continuity are magnified. Companies in a wide range of industries, where the presence of combustible and toxic gases are a way of life, must continue to evaluate their gas detection systems or pay the price on many levels. This evaluation must consider a number of factors that can enhance safety, while streamlining installation and minimizing maintenance – in the present and the future. That’s what constitutes a truly universal solution. 

Fixed Gas Detection with Legacy Technology/Instruments 

Before we look ahead and evaluate a truly universal approach, it’s important to take a look at how gas detection is done with legacy technology today…
  • a single detector is paired and tested with a single sensor, detecting only a single combustible or toxic gas; 
  • adopting new, advanced digital communication protocols necessitates replacing existing systems with new detectors and/or new sensors; 
  • unique certification requirements for different devices and regions complicate the ability to engage in business as a company expands its operations globally; • more points mean more maintenance and associated costs; 
  • a field technician’s toolbox is packed with multiple sensors, detector heads and accessories from multiple manufacturers, requiring major inventory investment; 
  • a large workforce with specialized knowledge is needed to address specific installation and service requirements; and multiple manuals, covering many different product lines, only complicate installation and impede productivity;
Engineering, Installation and Maintenance for a Universal World 

Call it a paradigm shift in response to customer needs. Today, there is an increasing call for higher levels of safety, performance, standardization, economies of scale, ease of use, and overall accountability. Meeting these needs and adding value to the customer experience begins with re-thinking fixed gas detection engineering. 

Engineering a universal gas detection system provides its own set of challenges. But these challenges are being met and needs are being fulfilled. As you position your company to leverage a truly universal gas detection solution, you must evaluate where you are and where you need to be. The following exploration of legacy systems used in the field today and truly universal characteristics of next-generation gas detection instruments should aid in your evaluation.

One to Many 
  • Legacy System: A single detector is paired with—and tested with—a single sensor, accommodating only a small number of combustible or toxic gases. 
  • Truly Universal System: A single gas detector accommodates multiple sensors, allowing you to detect multiple types of gases in one location. Working within the same device footprint the transmitter is designed to support different sensing technologies: combustible gas sensing with infrared and catalytic bead sensors and electrochemical and metal oxide semiconductor sensors for toxic gases. Using equally smart sensor technology allows the construction of sensors with multiple ranges in the same package which in turn enables range invariant calibration. One instrument that can provide the capabilities of multiple instruments, and one sensor that can support multiple gas ranges provides valuable flexibility not available in legacy gas detection devices. 
Communication Protocols 
  • Legacy System: Legacy systems have traditionally relied on analog signals for communication. This limits the transmission of advanced diagnostics data that ensures a safe plant environment. Adopting digital communication protocols necessitates installing new detectors and/or new sensors. 
  • Truly Universal System: As needs change and new communications protocols are required, universal transmitters are engineered to accept new plug-and-play communication boards. This multiprotocol innovation – wired or wireless (when industry appropriate) – means protocols can be added without replacing the transmitter as a plant’s communication requirements change. You’ll want to make sure your transmitter accommodates a wide range of communication protocols, including Modbus, HART, wireless HART and wireless ISA100.11A. This kind of flexibility is a key to a futureproof gas detection solution, and the transition from rigid, proprietary systems to standards-based, secure systems that accommodate growth and change.
Calibration and Maintenance 
  • Legacy System: Because of engineering constraints, sensor calibration must be performed in the field, where conditions are less than ideal and both safety and performance may be compromised. 
  • Truly Universal System: Accurate calibration is critical to satisfying both safety and performance requirements. It also impacts productivity when false alarms, due to inaccurate calibration, slow down – or even shut down – production. Imagine the consequences of an electrochemical sensor triggering an alarm that releases a blanket of foam. The cleanup costs alone can be staggering!

    Next-generation gas detection enables a calibration-in the-lab scenario, providing a more controlled and safe environment for establishing gas sensor parameters. This is a significant innovation, especially with legacy cat bead sensors which required proper voltage adjustments at the point of detection. Additionally, the flexibility to calibrate an electrochemical sensor to a particular gas level and then make simple adjustments to the range later—without recalibrating the sensor to the new range—can offer significant efficiencies in sensor maintenance.

    Through advanced engineering, a transmitter’s microprocessor can remember the type of sensor installed, as well as all calibration values. This built-in system of checks and balances virtually eliminates duplication of effort and the possibility of installing the wrong sensor. 
Global Standards 
  • Legacy System: Global certification, especially when deploying a variety of detectors, can complicate and delay the ability to engage in business as your company expands its operations. 
  • Truly Universal System: Expanding the certification of a gas detector for global acceptance (including CSA, ATEX, IECEx, INMETRO, GOST-R, China Ex, A & C Tick, Marine Directive - Ship’s Wheel/ ABS and SIL 2 certified by a third party agency), plays a critical role in facilitating quick global adoption. The process of seeking global certifications can be further streamlined when a single gas detector is flexible enough to accommodate a wide range of toxic and combustible gases.
Cost of Ownership
  • Legacy System: The presence of more points (i.e., detectors) means higher maintenance, more complexity and incremental costs associated with added cabling, junction boxes and wiring. 
  • Truly Universal System: Less is more – and better – when you can reduce the number of points in a gas detection system. One device consolidating three points has a positive ripple effect in terms of installation and maintenance. For instance, at a site with 45 points, accepted practice would include point-to-point wiring, using a Modbus communication protocol wired back to a central location or controller. But with a multi-head scenario, handling three points each, the number of detectors is reduced to 15 devices. This approach represents significant cost savings. In fact, using a single detector that consolidates three points, with a single relay board to control three alarms, totally eliminates a costly controller. Multiply this configuration times three for every three-head detector/multiple sensor configuration, and your cost of ownership is further reduced. 
Workforce Knowledge Base
  • Legacy System: Multiple manuals or the knowledge of many different product lines can slow the installation process and impede productivity. 
  • Truly Universal System: In today’s climate, it is becoming increasingly important to do more with a smaller, less specialized workforce. Truly universal engineering produces solutions that are simple to use with consistency in design making products intuitive, easy to learn and easy to use. This reduces installation time and increases productivity. 
  • Legacy System: Large inventories of sensors, detector heads and accessories demand a significant inventory investment. 
  • Truly Universal System: A field technician looks in his toolbox and sees fewer sensors, detectors and calibration adapters, as well as fewer accessories (like deluge guards and flow cells). Universal mounting kits simplify the process in new installations, while retrofits to existing installations are significantly more manageable. This simplification also minimizes lapses in safety due to human error. 

Exploring a series of “universal truths” about next-generation fixed gas detection is a critical first step in evaluating how you protect your people and maintain the highest levels of productivity. Truly universal gas detection begins with a singularly flexible system, engineered to ensure accurate performance in a wide range of environments; considers current and future manufacturing plant environments; and plays a significant role in keeping costs under control in the face of global certification requirements and a changing workforce. How you use this insight will impact where, and how successfully you conduct business.

For more information contact:
Power Specialties, Inc.
9118 E. 72nd Terrace
Raytown, MO 64133
Toll Free: (800) 432-6550
Phone: (816) 353-6550
Fax: (816) 353-1740

Yokogawa Data Acquisition Product Line Changes

Modern industrial process control has ever increasing demands for data acquisition. The ability to rapidly gather and process measurements into control and management decisions and reports is essential to efficiency, safety, and profitability. Yokogawa has been a leading manufacturer in the data acquisition sphere for decades, and has made some changes in its product line to maintain its leadership position.

The model CX 2000 was discontinued at the end of February. It combined data acquisition, display, control, and networking in a single unit. A scaled down version, CX 1000 was previously discontinued. The company recommends possible replacements to include one or more of the following products:
  • Advanced Application Temperature Controller UT75A
  • Button Operated DX1000/DX2000
  • General Purpose Temperature Controller UT35A/UT32A
  • Mid-level Temperature Controller UT55A/UT52A
  • TC10 Temperature Controller
  • Touch Screen GX10/GX20
  • US1000 Digital Indicating Controller
  • UTAdvanced UT32A-D
  • UTAdvanced UT32A-V/C/R
The DX2000 Daqstation is a mature product with a solid portfolio of field installations. It can accommodate display, recording, networking, and storage of data on up to 48 input channels. Input types include DC voltage, contact signal, RTD, and thermocouple. Ethernet connection enables remote access via a website and the unit can provide email alerts. There are numerous effective and user-friendly features included with the DX2000, which incorporates Yokogawa's decades of experience with recording and data acquisition.

Whatever your data acquisition needs and challenges, the best solutions will result from combing your process expertise with the knowledge of a product specialist. Reach out to them and get results.

pH Measurements for Corn Mash Slurry (Liquefaction)

Yokogawa pH / ORP Sensors
Yokogawa pH / ORP Sensors

Application Description

Many Ethanol plants running today are using a combination style pH electrode with a non-flowing reference to measure pH in the Mash Slurry transfer line from the Mash slurry mix tank to cook. The Mash is being pumped out of the Mash Slurry tank is at approximately 82 °C and 2 to 4 bar (180 °F and 40 to 60 psig). The original pH electrode systems that were installed during plant construction are online retractable assemblies and are mounted in orientations from completely horizontal to completely vertical and everywhere in between.

The Problem

The combination probe that is being used will typically drift out of calibration very quickly. Also, the probe is damaged sometimes from excessive removal from the process. The reason this probe drifts out of calibration is due to the fact that the non-flowing reference system plugs and becomes fouled by the mash passing by it. pH measurements are only as good as the reference required to make this measurement. If the reference is not doing its job, the measurement electrode will drift.

Dry Mill Process

Product Recommendations

Yokogawa manufactures a multi-probe holder called the FF20 – flow through fitting or the FS20, which is pH chamber assembly with 1⁄2” NPT process connections. With these holders we use a combination electrode, part number: SC21C-AGC55 for measurement and reference and a separate temperature sensor part number: SM60-T1. The Yokogawa electrode system works due to the fact that the SC21C-AGC55 combination probe uses a pressurized reference system. By using plant air regulated to a KCl reservoir, the SC21C-AGC55 utilizes a positive flowing reference that does not foul.

Plants using this system typically check the pH measurement against a grab sample and only make adjustments if the sample and the online measured values are more than 0.2 pH difference from one another. Typically, the system will not need daily or weekly calibrations. Most plants will pull the electrodes once a month for cleaning and calibration in a standard 4 and 7 buffer solutions. 

pH probe locations
pH Probe Locations
Installation Considerations

The Yokogawa pH system is not retractable from the process. It is usually best to put the Yokogawa pH electrodes in a by-pass or recirculation line that you can add isolation valves for isolating the probes from the process for maintenance and calibration. The probe assembly should be mounted downstream of the Slurry Tank transfer pump. Ideally it will be in a recirculation line going back into the tank or into the suction side of the slurry pump.

The picture below shows an installation that is actually flowing from left to right. The arrows indicate the direction of the mash flow through the recirculation line and back into the suction side of the pump. You will get an idea of the installation of the Yokogawa probes and the pressurized reference KCl reservoir from this picture. The reservoir pressure is typically set 1 to 2 psig above the slurry line pressure. The KCl reservoir will require refilling every 2-3 months for most applications.

For more information contact:

Power Specialties, Inc.
9118 E. 72nd Terrace
Raytown, MO 64133
Toll Free: (800) 432-6550
Phone: (816) 353-6550
Fax: (816) 353-1740