Electronics Engineering Magazine

Wednesday, May 19, 2010

Test Measurement Instruments by delabs

These are Instruments that Jack built. Here read Jack as me, delabs. Some were hand made, some in the form of workflow of a small firm with professional equipment. Some made in quantities, other a couple or more for R&D.

Test & Measurement Instruments

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 i 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.

Thursday, May 13, 2010

Industrial Control Panels and Instruments

Instruction Manuals of Process Control Instruments and Industrial Automation Solutions, Control Panel Diagrams, Wiring, and Facia.

Temperature and Pressure Controllers form a large part of Process control Instrumentation. Then you have Flow, Humidity and many more custom parameters.

All Real Life Physical Phenomena are reduced to Analog Numbers by Sensors and Transducers. This analog value is amplified and linearized and brought into standardized windows like 1-5 Volts or 4-20mA and more.

Industrial Control Panels and Instruments

These Analog Values go to Analog Closed Loop Controllers or Meters for Measurement and Control. In Embedded Controllers, the Analog is converted to Digital ( At least 12 bit, 8 bits are cheap not used for industrial automation, more than 16 bits is not required as sensor accuracy/linearity never transgress such precision )

Embedded Process Controllers may use Microcontrollers with Floating Point Arithmetic, Lookup Table, Logic and Basic Math. Advanced Controllers may use DSP and Complex Algorithms for Adaptive control. (self learn, fuzzy logic.).


There is a instruction sheet for a 3 wire transmitter. It Amplifies the uV signals from a K type Thermocouple, Chromel-Alumel. The output is a strong 4-20mA which is fit for looping and driving a Controller an Alarm and an Analog Recorder too.

8 Bits D/A may be used when a control signal is needed, like 4-20 mA Control Output driving a Thyristor PWM bank. Here 8 Bit is enough when the thyristor bank drives large heaters. The thermal inertia and delay makes very precise control nearly impossible.


When a parameter needs to be controlled in a tiny area, precision control is possible. A 16 Bit control signal is required. The system/thermal design here is more important than the controller, they have to be tandem for obtaining repeatable precision control.

Read More abou this here - Electronics Theory - Industrial Control Panels