Thursday, June 22, 2017

Test Measurement Instruments

delabs designed and built many custom "engineered" Test Instruments. They were not prefect, as only one or two were fabricated. That means it will be costly to produce such instruments. It is just like tooling, you have to make some numbers to recover costs, or price it very high to compensate for the wastages and iterations. But things are better off now for building custom instruments. Yet a design firm has to make modules and keep ready, then put together a solution/system, program and ship.

Test & Measurement Instruments

When making custom equipment, you have to have an extended service agreement like 5 years. Also request a minimum order of at least 5. Make your R&D and Inventory Modular. That way it is profitable and some money available for reinvestment on instruments and Equipment for calibration and quality.

Test Measurement Instruments by delabs

Test and Measurement is all about Measurement or Metrics. Without this, every other part of electronics becomes like boneless entities.

Relationship between Instrumentation and Automation - In Test and Measurement and Industrial Process Control a common factor is instrumentation. The measuring aspect is common to both. T&M instruments are used in Testing, Research,Automated Testing, Troubleshooting and Servicing.

Instruments designed and built. (long ago).
Process control Instruments are used in Production Lines made of Machines in a Factory. It could be Counters and Timers used for Textile or Steel Industry. It can also be Temperature and Pressure Controllers used in Oil Refining or Food Processing.

So you see a difference. We have handheld Test Instruments like DMM and Scope and We have Handheld Instruments for Gas Monitoring or Humidity too. In automated testings we have rack mount test instruments. In Control panels we have Rail Mount carrying DIN standard Instruments.

Monday, April 24, 2017

Instrumentation and Measurement Circuits

Analog Circuits are the core in any instrument design, Even in a Instrument with Digital or uC control. The Interface to the Real World parameters is Analog. High Speed Analog and High Energy Measurements are the challenging areas.

T&M and Process Control Instrumentation have many things in common; but the conditions in which a Industrial Instrument works, may be very unfriendly.

Instrumentation and Measurement Circuits

Industrial Instruments are used both in Clean-Cool Control Rooms and also in a corrosive, humid, hot and vibrating industrial environment. Even high levels of Static, Magnetic influences in conjunction with spikes and brown outs can be expected.

Instrumentation and Measurement Circuits

Test and Measurement instruments are of two types, by way of its usage; Portable and Benchtop. Portable Instruments will consume low power, insulated and rugged. The Product Safety features are more stringent as they are HandHeld or slung over the shoulder. Some features and specs are sacrificed. The Benchtop version has more front panel space and can interface with other instruments or systems. More accuracy and features can be accommodated in this.

Basic Measurement
Other Circuits on this page are - in PDF -
  • Linearizing circuit  using opamps
  • Universal signal conditioner differential amp
  • Simple MilliVolt Source
  • 0-2V to 4-20mA Converter
  • Analog averaging circuit with Opamps 

Monday, February 13, 2017

Process Control Application

A Closed Loop Control System is the most important aspect of Maintenance, Regulation and Stability in any Live Process. Nature itself is self regulated in an intricate fashion, a keen observer can notice the subtle controls. In Human Created Industrial systems we have Process control as a complex science. We can start by understanding a Simple One.

Process Control Application Notes

When you fill a Bucket with water, You keep an eye on the Level of water, as you open the Analog Tap, which is an equivalent of a Motor operated Valve. Your Eye is an advanced Optical Sensor, which is able to sense the level by the computation in the brain, which in turn operates the muscles of your hand, thru the nervous system. The hand along with the Water Tap is is the Actuator. As the water fills up close to the top, you start reduction of the water flow and keep observing, then as it tops up, you tweak the tap to a trickle. When it reaches the limit you shut off the tap.

Closed Loop Control Systems

While you are half way filling the bucket, what happens if you take a short nap, or a friend comes by and you are get absorbed in conversation, the water overflows and goes waste. Then someone raises an alarm after the Runaway process happens. This is of minor consequence, but it is not so in the case of Temperature, Pressure and also many common systems like the driving of an Automobile. Remember the gears, brakes, accelerator to control and steer the car to the correct destination, a Runaway Process causes an accident.

Monday, January 2, 2017

Tutorials on Basics and Instrumentation

Theory must be studied once and referred to, again and again as you do practicals. One is by building DIY projects and then modifying them. Also Repair of equipment, troubleshooting, testing and calibrating. Then you know how components behave and real life limitations. Now design and engineer a product and test it at customer site. do a pilot production and test with more clients. Now you will learn to think based on practical applications.

Tutorials on Basics and Instrumentation Electronics

This invention lead to modern electronics, computers and internet look at this page, Transistor Photo.

History of The Transistor

A picture of the first transistor ever assembled, invented in Bell Labs in 1947. It was called a point contact transistor because amplification or transistor action occurred when two pointed metal contacts were pressed onto the surface of the semiconductor material.