Friday, August 26, 2011

Selecting a Thermometer

When selecting a thermometer, it is important to consider the dial or case size, stem or capillary length, and the connection type and temperature range. To ensure safety and accuracy, thermometers should be selected while giving consideration to the measured media and the ambient operating conditions. Improper application may be detrimental to the thermometer, causing failure and possible personal injury or property damage.

While there are 3 basic operating types of thermometers, they being bimetal, liquid-in-glass, and Bourdon tube, the list can really be expanded to also include RTD and solar digital thermometers. All five types may appear suitable for any typical applications, however, the correct selection depends upon the industry being served and the application specified.

The following will serve as a general overview of each of these thermometers.

Bi-metal Thermometers
Bi-metal thermometers are direct sensing instruments. They are hermetically sealed and therefore, completely waterproof. All bi-metal thermometers are made of stainless steel to protect against corrosive conditions.

How they work: Two different metals with different coefficients of thermal expansion are bonded together.
As temperature changes, the unequal expansion of the two metals will cause the bimetal strip to curl, causing a displacement. This displacement is transferred from a ridged shaft to a delicate spring that drives the pointer.

Liquid-in-glass Thermometers
Also known as liquid expansion thermometers, liquid-inglass thermometers are perhaps the most popular type of thermometer. There are two types of liquid-in-glass thermometers: industrial and laboratory.

How they work: These thermometers indicate pressure by measuring expansion and contraction (i.e. as the fill liquid is heated, it expands and rises). The temperature is indicated on the vertical scale next to the fill liquid in the glass tube.

Remote Reading Thermometers
By means of a capillary tube with a sensing probe at one end and an indicating dial on the other, temperatures can be determined from a source that is up to 30’ (100m) away.

How they work: The capillary of the thermometer is filled with a gas or vapour. As temperature changes, the gas or vapour expands/contracts, creating pressure that is measured by a Bourdon tube. Some of the most common capillary fills are nitrogen (in gas thermometers) and isobutene (in vapour thermometers). Consider factors such as ambient temperature, humidity, installation, indoors or outdoors, presence of dust, corrosive atmosphere, mechanical shock, frequency and magnitude of vibration.

RTD (Resistance Temperature Detector)
When an application requires remote reading capability combined with high accuracy, a Resistance Temperature Detector (RTD) may be the best option.

How they work: RTDs work by reading the resistance charge across a metal wire that is produced from each temperature input. RTDs can be supplied with a transmitter fitted inside the RTD head to provide an industry standard 4-20mA output signal.

Solar Digital Thermometers
Digital readouts are sometimes preferred in some industrial environments. Expansion and bi-metal sensing thermometers are both available with digital readouts and solar powered.

How they work: The temperature reading is captured by a sensor that relays the data to a digital display. No additional power supply is required to power these thermometers. These thermometers require between 16 to 35 lux of illumination.

Tuesday, August 16, 2011

New Training Classes Are Now Available!

We are continuing to update our training class offerings. During the second half of 2011 we will be offering two new courses, diligent design & selling hydronics. Both classes are full days and are taught by Bruce Marshall. The diligent design course focuses on maximizing ROI by utilizing new concepts in heating. Energy efficiency and new technologies will be discussed. Our selling hydronic course teaches the art of the sale. We focus our attention on ways to make you more profitable in your business and give you some tips to close the deal. Come check out these and all of our available courses at our new website. You can browse all course offerings and sign-up online as well. Hope to see you soon!

Thursday, August 11, 2011

Why Turndown Ratio Matters

In their smallest form, devices intended to heat water or other fluids using a chemical fuel (coal, gas, oil, electricity etc.) are usually thermostatically controlled. When the desired operating pressure/temperature is attained, the thermostat turns off the heat source. When the pressure/temperature has fallen (usually to a pre-determined level), the thermostat turns the heat source on. The heat source has only two states, ie on or off. This is undesirable in all but the smallest devices as the fluctuations in pressure/temperature lead to inefficiencies in fuel combustion/consumption.

If the heat source can be made to modulate, there can be considerable savings in fuel due to combustion processes and heat/wet side temperature differences. Pressure/temperature output can remain more constant which may be of benefit.

If it is only possible to turn the output of the heat source down to (for example) 50% of its maximum. This would give a turndown ratio of two. If the heat source could be turned down to 25% of its maximum value, the turndown ratio would be four and so on.

This means that if pressure/temperature falls, the heat source is progressively turned up.

The HTP Elite boiler has a best in class 6 to 1 turndown ratio which provides the high efficiency performace that today's cunsomers want. Made in the USA, the Elite boiler is energy star rated and built with quality. The Elite boiler comes in six models ranging from 80,000 btu - 399,00 btu making it suitable for any application.

Thursday, August 4, 2011

Who Wants Red Sox Playoff Tickets?

Anyone? Well if you do, you're in luck! Emerson Swan is giving away a pair of playoff tickets for the 2011 season. Simply go to our website and fill out the short form. We will announce the winner at the beginning of the playoffs. Good luck!

Tuesday, August 2, 2011

The Future In Water Heaters

Voltex® Hybrid Electric Heat Pump water heaters are the most versatile, energy-efficient option for the consumer who is looking to go green and save some green. Voltex can provide the same amount of hot water as a conventional electric water heater at half the cost. The Voltex® Hybrid Electric Heat Pump Water Heater is an integrated system that utilizes heat pump technology to provide a more efficient way to heat water with electricity. The Voltex pulls heat from the surrounding air and deposits the heat into the tank. The end result is very efficient production of hot water, with cooler and dehumidified air as a welcome by-product.

         Absorbs environmental heat and transfers it to the water, at the same time cooling and dehumidifying the ambient air
         With an 80-gallon tank, more energy is created through the heat pump technology, resulting in larger savings
         Four operation modes: high efficiency, hybrid, electric and vacation
         User-friendly LCD display for easy interaction
         Conserves energy thanks to 2.4 Energy Factor (EF)
         Eligible for Federal Tax Credit 
         ENERGY STAR® qualified
         Available in 60 and 80-gallon models

Learn more about the Voltex® Hybrid Electric Heat Pump here.