It’s here! The Process Heating & Cooling Show kicks off today at the Donald E. Stephens Convention Center in Rosemont, IL. Be sure to stop by booth 313 to meet the Dwyer Instruments and Omega Engineering teams, and learn how we can help with your next process automation project.
Imagine you sit down at a restaurant on the outdoor patio, and as you’re waiting to order your food, you glance at the large HVAC system on top of the building across the street. Several questions cross your mind: Why do they need such a big system? And what goes into it? Today I want to introduce one of the vital aspects of a building’s HVAC system, the air handler. Continue reading “What is an Air Handler?”
Dwyer Instruments, Inc. offers a wide variety of temperature sensors that use RTDs as the sensing element.
RTDs are based on the principal that the electrical resistance of the wire is a function of the temperature, with the resistance increasing as temperature increases. The resistance varies nearly linearly with temperature per the Callendar Van-Dusen equation. The wire used in RTDs as the sensing element is usually constructed of platinum, copper, or nickel. Platinum is the best material for this element, as it has the widest useful temperature range of these materials. It also has a very repeatable and linear temperature to resistance correlation. Continue reading “RTD Temperature Sensors”
Thermistors are based on the principal that the electrical resistance of semiconductor materials is a function of the temperature. Thermistors work well over smaller temperature ranges with better accuracy than (RTD) but are very non-linear. They also generally offer better response times. Thermistors have much higher resistance values than RTDs, with ranges typically ranging from 100 ohms to 100 megaohms.