Control Engineering’s Process Instrumentation Enewsletter –June 2000

By Dick Johnson May 31, 2002

In this issue:

  • Introduction
  • Fiber-optic level sensing
  • Sensing more of what goes up the stack
  • Keeping tabs on engine oil levels
  • Monitoring H 2 S

  • Archive
  • Sensors go hypersonic?

Looking through a different window

Just in case you do not recognize this newsletter from Control Engineering magazine, it is new this month. The editor in charge of this offering is yours truly, Dick Johnson . I am the Senior Editor that handles Instrumentation and Process Sensors for the magazine and I will do my best to treat the same subject-often from a slightly different or expanded perspective- in this new medium. I intend to make this venue a conversation of sorts. Even though I seem to be doing all the ‘talking,’ I look forward to hearing from you. Email me at .

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Fiber-optic level sensing

Brooksville, Fla.- Looking for a safe way to measure level in flammable or explosive liquids, Kinematics & Controls Corp. has designed fiber-optic level sensors that are said to provide either point level control or monitor leak detection with the use of electrical power at the point of measurement. The Series 5134 Fiber-Optic Sensor is intended for use in process or OEM applications. Theost fluids regardless of color. The sensors function remotely with the developer’s Series 5135 liquid level controllers.

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Sensing more of what is going up the stack

In a meeting held at the U.S. Environmental Protection Agency (EPA) facility in Research Triangle Park, N.C., the consensus was clear. Eight CEM vendors and 20 observers including regulators from four states felt it was time to conduct verification testing of continuous emissions monitors for mercury. The U.S. EPA is considering regulating mercury emissions from coal-fired power plants or incinerators nationwide, which might require the uses of mercury CEMs in those facilities. Phase 1 of the proposed testing will include verification of relative accuracy, calibration/zero drift, calibration error, precision, interference, and response time in a pilot facility that provides to ‘mercury-spiked’ flue gas to available instrumentation. Phase 2 is planned at a full-scale facility and is yet to be determined.

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Check that oil!

Keeping tabs on engine oil levels in industrial prime movers is critical. Low or rapidly falling levels can signal impending equipment disaster and process shutdown. Gentech International has developed a sensor for use in engine oil level detection that is said to offer precise switching even in the extreme engine environment. The actuating float of the sensor is housed in a column-style shaft with liquid entrance and exit holes, facilitating precision switching of level rise and fall in the turbulence of an engine sump. The sensor housing is 30% glass-filled Nylon 6.6 and the float is 15% glass-filled Nylon 6.6 to give buoyancy even with widely varying temperature and viscosity changes. The device, which is available from Power Components of Midwest Inc. (Mishawaka, Ind.) has a single hookup cable and metal base plate that grounds to the engine sump.

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Remembering that chemistry experiment gone wrong

Ask most people about what they recall about high school chemistry class and they may be quick to reply, ‘That awful rotten egg smell!’ Hydrogen sulfide’s characteristic odor may act as an early warning device of sorts but even in mildly elevated concentrations it is both dangerous and corrosive. Control Instruments Corp. (Fairfield, N.J.) uses electrochemical technology for monitoring H 2 S in the ppm range. The sensor incorporates a capillary barrier, which eliminates the possibility of puncturing problem. The highly accurate device is said to feature excellent repeatability and long-term stability for zero and span setting. Other features include an on-board heater for subzero operation. The sensors only require 100-ppm oxygen for operation. Possible applications include chemical and petrochemical plants, oil and gas production, wastewater treatment, and pulp and paper mills.

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25 years ago in Control Engineering, the June issue presented Controls ’75, the first organized listing of control suppliers and control equipment ever presented by the magazine. Instrumentation listed included Action Instruments (San Diego, Calif.) Model SP-91-4051 pressure transducer providing voltage outputs up to 10 mV, a National Sonics Corp. (Farmingdale, N.Y.) high frequency-based Model 501 explosion-proof and watertight liquid level switch, and Superior Switchboard & Devices (Canton, O.) test switches for instrument calibration.

45 years ago in Control Engineering, the final installment of a three-part article ‘How Temperature Compensation Can Be Used,’ by Robert Gitlin, Servomechanisms Inc. appeared. The series discussed the effects of temperature change on instrument accuracy and presented ways to compensate for these effects.

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Sensors go hypersonic?

Don’t miss this one! NASA’s X-43 Research Model Aircraft will be on display in the Sensors Pavillion at ISA Expo/2000 scheduled for August 21-24, 2000 at the Ernest N. Morial Convention Center in New Orleans, La. The X-43 was developed to flight test a dual-mode ramjet/scramjet propulsion system at speeds from Mach 7 up to Mach 10. The X-43A/Hyper-X program is part an experimental flight-research program seeking to demonstrate airframe-integrated, ‘air-breathing’ engine technologies that promise to increase payload capacity for future vehicles, including hypersonic aircraft and reusable space launchers. First flight is scheduled in 2000.

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