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Your email address will not be published. Website :. Save my name, email, and website in this browser for the next time I comment. There are some advantages of optical pyrometer which are given below. The optical pyrometer is useful for high temperatures. It is useful for monitoring the temperature of moving object and distant objects. It has good accuracy. No need for contact with target of measurement. It is light in weight. There are some disadvantages of optical pyrometer which are given below.

The accuracy may be affected by dust, smoke and thermal background radiation.

disadvantages of thermometer

The optical pyrometer is not useful for measuring the temperature of clean burning gases that do not radiate visible energy. It is more expensive.

It causes human error. Optical pyrometer. Like 17 Dislike 1. Related Articles: Difference between radiation pyrometer and optical pyrometer Advantages, disadvantages and applications of radiation… — disadvantagesapplications of radiation Difference between radiation type level measurement and… Optical transducer Advantages, disadvantages and applications of radiation…. Leave a Reply Cancel reply Your email address will not be published.What are the advantages and disadvantages of liquid in glass thermometer?

Following are the major advantages associated with the use of liquid-in-glass thermometers: They are comparatively cheaper than other temperature measurement devices. They are handy and convenient to use. Unlike electrical thermometers, they do not necessitate power supply or batteries for charging. See Full Answer.

disadvantages of thermometer

How does the liquid in glass thermometer work? A LiG thermometerby definition, is a glass capillary tube with a liquid -filled bulb at one end.

As the temperature of the liquid in the reservoir increases, it expands and rises into the capillary tube. Since the object weighs more than the mass of the water it displaces, it sinks. This shows that very small changes in the density of the liquid can easily cause an almost-floating object to sink. In the Galileo thermometerthe small glass bulbs are partly filled with different-coloured liquids. The mercury-in-glass thermometer was invented by Daniel Gabriel Fahrenheit in Amsterdam It is a bulb containing Mercury attached to a glass tube of narrow diameter.

The volume of mercury in the tube is much less than the volume in the bulb. The volume of mercury changes slightly with temperature. Unlike the mercury -in-glass thermometer, the contents of an alcohol thermometer are less toxic and will evaporate quickly. The ethanol version is the most widely used due to the low cost and relatively low hazard posed by the liquid in case of breakage.

What is a liquid thermometer used for? Liquid thermometers are the most common type in use. They are simple, inexpensive, long-lasting, and able to measure a wide temperature span.

The liquid is almost always mercury, sealed in a glass tube with nitrogen gas making up the rest of the volume of the…. Mercury is the only one in liquid state at room temperature. It's used in thermometers because it has high coefficient of expansion.Fever may be an alarming symptom in various conditions, including infections such as common cold, pneumonia, urinary tract infections, meningitis, etc.

Other non-infectious causes that may result in elevated temperature include autoimmune diseases, cancer, tissue destruction and drugs side effects. In addition certain variations of body temperature during the day may be associated with specific conditions malaria for example. On the other side extremely low body temperature known as hypothermia is also dangerous for the normal body functioning. This underlines the importance of accurate temperature measuring methods and instruments.

However, oral temperature along with rectal temperatureif taken correctly, is currently considered as very reliable. Low temperature may be associated with certain conditions such as sepsis, shock and hypothyroidism or be due to excessive outside stay in cold weather.

These values may vary depending on the model of the thermometer you use. Manufacturers usually provide information on the ranges for every different device that you should consult in order to interpret correctly the measured temperature. Oral temperature normal ranges vary between Oral temperature can be measured through:. Digital oral thermometers are very accessible and easy to use. Many kinds of digital thermometers are available on the market and can be bought at either grocery stores or pharmacies.

Generally, the tip of the thermometer contains thermistor that detects the physical temperature and converts it into electrical energy.

Temperature is being measured for several seconds and the result is then being displayed on the LCD screen of the device. Most of the thermometers are equipped with a sound alarm that marks the end of the measurement.

Another sound may be produced if fever is being detected. The majority of the digital thermometers also offer memory function. To obtain an accurate result, always follow the instructions provided by the manufacturer of the device. In order to measure the temperature using a digital thermometer, you should keep its tip under your tongue, mouth firmly closed until you hear the beep-alarm. It usually takes 10 to 60 seconds, depending on the model you use.

Clean the thermometer after each use. Glass thermometers contain a tiny tube filled with liquid usually ethanolnitrogen and ethanol vapors. The liquid could be colored for easier interpretation of the results.IR thermometers are handy for use in measuring drafts and insulation breakdown.

They can pick up hot spots in electrical systems and bearings and help monitor cooling systems. They are even used to measure food storage temperatures and can do this with no cross-contamination.

Certainly this technology has many benefits. However, it also had a few disadvantages. Infrared sensors offer the same technology and features as infrared thermometers except they output different signals.

They can output thermocouple, voltage, or analog signals to displays or controllers. These sensors are excellent for measuring multiple points in a process and are economical. Use industrial infrared sensors when the high temperature of the target to be measured could damage or destroy a contact sensor. View our selection of infrared thermometers or infrared sensors. Hey, Thank you for sharing your expertise on Infrared Thermometer.

I was not in impression that Infrared Thermometer having any kind of disadvantages. I actually thought that the disadvantages could have been a bit more detailed. It was rather interesting to read, though.

Infrared in Space November 5, at am Reply. Leave a comment Cancel reply Your email address will not be published.Why don't fictional characters say "goodbye" when they hang up a phone? If we can't tunnel through the Earth, how do we know what's at its center? All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply. Hottest Questions. Previously Viewed. Unanswered Questions. What are the disadvantages of a forehead thermometer?

Wiki User The disadvantages of forehead thermometer is thatit is not always accurate, and the screen cant be seen well after a while. It is a thermometer used to tell body temperature by placing it on the forehead. It can be easier to use in the case of a child. Asked in Temperature What are the ways of getting the body temperature?

Advantages and disadvantages of resistance temperature detector (RTD)

Asked in Body Temperature Do you get the accurate temperature reading from the forehead if it is wet? If you are referring to using a surface thermometer, no. Asked in Physics What are the disadvantages of a clinical thermometer? Asked in Physics What are the disadvantages of a liquid thermometer?

You usually have a temperature when your forehead, cheeks, and chest is hot or you can get a ummm I for got what it was called but I think it was a thermometer. Asked in Pediatric Conditions and Diseases Does a forehead thermometer read higher or lower than a rectal thermometer on a 2 month old baby? At all ages rectal temperature is higher than skin temperature.

Asked in Body Temperature What is the thermometer that measures body temperature? Your question sounds a bit wrong, so I assume you mean "What type of thermometer is used to measure body temperature" The answer: you can use FeverTemp d ear thermometer more precise but more expensive I hope that answers your question.

Asked in Health, Parenting and Children What is best way to take child's temperature? Probably a thermometer or if you dont have one feel how hot their forehead is with your hand. Oral Thermometer When people think of a thermometer, they may think of the traditional glass thermometer placed in the mouth. Today, most oral thermometers are digital and made of some sort of plastic. These are used by placing the thermometer under the tongue and waiting for the alert that the reading is complete.

Some oral thermometers can also be used as rectal thermometers. Tympanic Thermometer Tympanic thermometers are used by inserting the thermometer into the ear. The thermometer has a cone shaped to fit inside the ear canal. However, according to Consumer Reports, this type of thermometer is not accurate in young children and must be perfectly aligned to get an accurate temperature.A thermistor is a semiconductor device formed from metal oxides.

Laser thermometers uses, advantages and disadvantages

The principle of temperature measurement with a thermistor is that its resistance changes with temperature. Most thermistors differ from normal resistors in that they have a negative coefficient of resistance, this means that the resistance decreases with an increase in temperature. A thermistor is a bulk semiconductor device, and as such can be fabricated in many forms. The more common include discs, beads and rods. There are different types of the thermistor, most of them are differ their response to temperature changes.

Thermistors are not linear, and their response curves vary for the different types. Some thermistors have a near linear temperature resistance relationship, others are available with a sharp change in slope sensitivity at a particular characteristic temperature. They are available in a large range of resistivities, with varying linearity.

Some thermistors have a large change in resistance to a change in temperature. Selecting these types makes for very good narrow span measurement, the temperatureversuss resistance characteristics is shown below. You must be logged in to post a comment. Skip to content Instrumentation. April 3, March 12, March 6, December 19, December 7, November 14, November 9, November 1, October 28, October 22, Sivaranjith News Reporter Instrumentation Engineer. Thermocouple basics and types of thermocouple.

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disadvantages of thermometer

Join Us.Thermometers are designed to measure temperatures within specific ranges for various purposes. Historically, mercury thermometers have been used for nearly all temperature measurements because of their accuracy and low cost.

However, their use is increasingly being restricted to industrial and scientific applications, as safety and environmental issues are demanding stricter laws on the disposal of products containing mercury. Thermometers are typically constructed of a hollow glass tube with a reservoir at one end to hold a liquid, which is sensitive to temperature fluctuations within a specific range. Mercury in its liquid form has traditionally been used because of its fluid properties of separation and adherence through temperature extremes.

It is identified by its familiar silver metallic color. Thermometers containing a blue or red color liquid are most often utilizing an organic fluid, usually alcohol-based.

Visual indicators are marked in degrees Fahrenheit, Centigrade or both. The coefficient of thermal expansion describes how the size of an object changes with a change in temperature. When something changes temperature, it shrinks or expands in all three dimensions. In a mercury- or alcohol-filled thermometer, it is the change in fluid volume that is important. Specifically, it is calibrated and measured at the volume per degree change in temperature at a constant pressure. Expansion or contraction of the glass tube and reservoir enclosing the liquid within is negligible, since liquids generally have a substantially larger coefficient of thermal expansion than solids.

The manufacturer calibrates and marks the thermometer so the top of the fluid column meniscus indicates an accurate temperature reading. Mercury thermometers are inexpensive, durable and accurate.

However, they present many safety and environmental hazards. Metallic mercury in its liquid state is relatively harmless when confined. However, in a gaseous state, as organomercuric compounds or as inorganic salts, it becomes a deadly toxin.

Mercury is especially harmful to fetuses, infants and children.

Comparison of Resistance Thermometers and Thermocouple

The metallic mercury in thermometers, if introduced into the environment in a non-controlled manner, can eventually enter the water ecosystem, where microorganisms break it down to methylmercury components. Fish and sea animals at the top of the food chain of the ocean, lakes and streams consume these compounds in their diets, where they tend to accumulate in their body tissues. According to Medicinenet. Alcohol thermometers are also inexpensive and durable.