industrial instrumentation basics

 How to Calibrate a Gas Analyzer If you've spent any time around a kiln, boiler, or any combustion process, you already know the drill:  the gas analyzer is the one instrument nobody thinks about until it starts lying to you. And it will lie to you eventually   every sensor drifts, every optical bench gets dirty, every electrochemical cell ages. Calibration is just how you catch it before it costs you. Here's the thing most manuals don't tell you plainly:  calibration isn't one procedure, it's three habits  zero span  a sanity check  done consistently, on a schedule you actually follow. Why It Drifts in the First Place Before touching any buttons, it helps to know what you're fighting: Electrochemical cells (O₂, CO, NOx sensors) slowly consume their internal electrolyte. Output drops over months, sometimes faster in hot, dusty environments. NDIR (non-dispersive infrared) benches drift when the optical path gets coated with dust or moisture, or whe...

  Types of valve  There are many different types of valves, some types are discussed below. Gate Valve Gate valve resembles to a gate so their name is gate valve. Gate valve are used mostly for on off services. Gate valve is made up of a plate like a gate, that moves up and down on a saeat to allow the flow or stop the flow.  Gate valve are sliding motion or linear motion valves. Stem of gate valve moves perpendicular to the direction of fluid flow. Applications of Gate valve  Gate valve can work well in high temperature and pressure applications.  It is preferred to be used for clean fluid flow control. Gate valves are fully sealed. Gate valve have low pressure drop. Gate valves are not considered good to be used for slurry or viscous fluids. Gate valve seat disc wears in partiality open position. Gate valve causes vibration. Globe Valve Globe valve is made up of a plug or disc that moves up and down on a sear to allow or stop the flow. Travel path in globe val...