What is Stability and Why is it Important?

Stability is defined as a change (or lack of change) in accuracy over a period of time.

Drift is commonly used as a specification to illustrate the stability, or change in accuracy over a period of time, commonly shown as X%/year where X = a number; i.e. 0.25%/year. In this scenario, a device with a ±1% accuracy, would be expected to have an accuracy of ±1.25% (1%+0.25%) after a period of one year. Depending on the design, brand, and range of the sensing instrument, the stability can vary widely. Continue reading “What is Stability and Why is it Important?”

Lift Station Level Sensing

Are you having problems with your current lift station level controls?  Dwyer Instruments may just have the cost effective solution you need.  In this article we will review several level sensing strategies, the advantages and disadvantages of each, as well as an option you may want to consider for your next project.

Lift Station Basics

In an ideal gravity fed wastewater collection system, sewage would flow downhill from its point of origin in residential or commercial areas to its final treatment plant destination.  Due to a number of factors including total distance, topography, geology, economics, etc., the ideal piping design is not always feasible.  Therefore, in most cases, sewage flows downhill to a lift station where it collects and then is pumped to a higher elevation in order to begin its downhill journey again. Continue reading “Lift Station Level Sensing”

Sump Level Make-Up Water Controls in Wet Chemical Scrubbers

Maintaining efficiency in wet chemical scrubbers has become one of the most important missions of current APC facilities due to urban growth and plant expansion/modernization projects as good stewards of the community. Systems often run above the 90% efficiency mark with the help of accurate make-up water control instruments. Continue reading “Sump Level Make-Up Water Controls in Wet Chemical Scrubbers”

Why Choose a 38R Self-Acting Control Valve?

There are several reasons why a 38R is a great choice in your heating or cooling applications, with the most obvious being that there is no power required. The 38R temperature regulator is a fully self-contained unit, requiring no external power source. This could mean substantial savings over the operation of other types of valves.

Regulation takes place when the sensing bulb  is exposed to changes in temperature. The thermal system is charged with a predetermined amount of vapor fill, which, when heated, will cause a bellows within the unit’s actuator housing to expand. As the bellows expands, it compresses a return spring while simultaneously moving the valve stem downward to stroke the valve.
When the process temperature decreases or in the event of thermal system failure, the return spring will move the valve stem upward to the “out” position. Continue reading “Why Choose a 38R Self-Acting Control Valve?”

Pressure Transmitters: Increasing Efficiency and Safety

As industries such as building automation and water/wastewater become more energy-efficient, powder and bulk is also increasing energy efficiency using pressure transmitters and variable frequency drives. Pressure transmitter demand is also growing due to more stringent regulations in hazardous environments, where remote control and specialty housings must be available.

Photohelic® Pressure Switch/Gage, Series A3000

With a typical dust collection system, a pressure sensor (such as our Series A3000 or Series DHII) can measure differential pressure across filter bags. The sensor then sends a switched signal to a timer board (such as the Series DCT500A or DCT1000) to signal a filter cleaning. Pressure in the system is created by a blower, typically positioned near the filter banks on top of the hopper. The system can also use a level switch (like our Series PLS and Series CLS2) to signal a full hopper and possibly open a valve to empty the hopper. So how do pressure transmitters reduce energy consumption? And how can you prevent an explosion in a hazardous environment without the additional cost of specialty enclosures? Continue reading “Pressure Transmitters: Increasing Efficiency and Safety”