precautions while using laboratory thermometers
. A thermometer is used to measure the temperature of an object. Galileo invented a rudimentary water thermometer in 1593. He called this device a thermoscope. However, this form was ineffective as water freezes at low temperatures. In 1714, Gabriel Fahrenheit invented the mercury thermometer, the modern thermometer. The long narrow uniform glass tube is called the stem of a thermometer. The scales in which the temperature is measured is marked on
. Laboratory thermometers are devices used to measure temperature. There are many types of lab thermometers such as differential, mechanical, logging, etc. Laboratory thermometers are progressively providing digital reading displays and are inputcapable to computer and software programs for logging purposes.
Types of Thermometers
. There are different types of thermometers that measure the temperatures of different things like air, our bodies, food and many other things. There are clinical thermometers, laboratory thermometers, Galileo thermometers and digital remote thermometers. Among these, the commonly used thermometers are clinical thermometers and laboratory thermometers.
. These thermometers are used to measure the temperature of the human body, at home, clinics and hospitals. All clinical thermometers have a kink that prevents the mercury from falling down rapidly so that the temperature can be noted conveniently. There are temperature scales on either side of the mercury thread, one in Celsius scale and the other in Fahrenheit scale.Since the Fahrenheit scale is more sensitive than the Celsius scale, body tempera
Mercury laboratory thermometers
. Mercury laboratory thermometers, used in some science laboratory, requirer special safety precautions. Alcohol laboratory thermometers, despite of its less dangerous nature, should still be handled carefully to any damage. There are several principles on which empirical thermometers are built, as listed in the section of this article entitled Primary and secondary thermometers. Several such principles are essentially based on the constitutive rel
. You have to twist gently the laboratory thermometer and press it firmly, but dont use brute force when inserting a laboratory thermometer to a rubber stopper. If you could, put a drop of glycerin or other lubricant to make the laboratory thermometer slide more easily.
. You have to hold your hand with distance of less than 1 inch from the stopper to avoid exerting torque on the thermometer. Thermometers can be divided into two separate groups according to the level of knowledge about the physical basis of the underlying thermodynamic laws and quantities. For primary thermometers the measured property of matter is known so well that temperature can be calculated without any unknown quantities. Examples of these a
. Laboratory thermometer safety depends on the type of laboratory thermometer: broken alcohol thermometers and other nonmercurylaboratory thermometers only needs the same cleanup as any other broken glass. A broken mercury thermometer requires special cleaning procedures.
. High school and college students should never try to clean up a mercury spill from a broken mercury laboratory thermometer; instead, tell your laboratory instructor, turn off any heat sources. Trained department staff will come to clean up the spill.
. Temperature is a measure of the degree of hotness or coldness of a body. The SI unit of temperature is kelvin (K). But temperature is usually measured in celcius (
Mercury Spill Cleanup
. Personnel responsible for cleaning up a mercury spill, according to Princeton, should wear protective clothing, gloves and goggles, and use index cards to sweep the contaminated material into a sealable jar. Never use a vacuum cleaner or sink. Label the jar, and deliver it to a hazardous waste facility.
. Mercury thermometers, used in some science labs, require special safety precautions. Alcohol thermometers, though less dangerous, should still be handled carefully to avoid broken glass. Secondary thermometers are most widely used because of their convenience. Also, they are often much more sensitive than primary ones. For secondary thermometers knowledge of the measured property is not sufficient to allow direct calculation of temperature. They
Uses at home clinics and hospitals
. Thermometers are used to measure the temperature of the human body, at home, clinics and hospitals. When performing this procedure, hold your hand less than 1 inch from the stopper to avoid exerting torque on the thermometer. Thermometers can be calibrated either by comparing them with other calibrated thermometers or by checking them against known fixed points on the temperature scale. The best known of these fixed points are the melting and boi
. Lab thermometer safety depends on the type of thermometer: broken alcohol thermometers and other nonmercury thermometers only require the same cleanup as any other broken glass, according to University of Illinois at Chicago. A broken mercury thermometer requires special cleaning procedures.
Points to kept in Mind while using a thermometer
. The thermometer should be protected from sudden changes of temperature. Never wash a hot thermometer in cold water or put a cold thermometer in a hot bath. For correct reading of temperature see that the thermometer is vertically and your eyes are exactly in line with the mercury level. Mercury on heating expands. Even a small expansion of mercury in the bulb of the thermometer causes a considerable rise in the capillary tube.
Precautions while using a clinical thermometer
. While putting the clinical thermometer in the mouth do not press it with your teeth. Hold it simply with the help of your lips. A slight pressure by teeth may result in the breaking of the thermometer bulb and release the mercury in the bulb. Mercury is poisonous. In case of children, the thermometer should not be put in their mouth. It should be kept under armpit. Half a degree is added to the reading in the thermometer. This gives the body temp
HowLaboratory Thermometers work
. The way a laboratory thermometer works depends upon its type. They are generally a liquidinglass device, a bimetallic strip, an electronic thermistor thermometer, or infrared (IR) device. Many empirical thermometers rely on the constitutive relation between pressure, volume and temperature of their thermometric material. For example, mercury expands when heated.
Selection Criteria for Laboratory Thermometers
. The GlobalSpec SpecSearch database allows industrial buys to select laboratory thermometers by type, display options, operating environment, and specialty features. Thermometers may be described as empirical or absolute. Absolute thermometers are calibrated numerically by the thermodynamic absolute temperature scale. Empirical thermometers are not in general necessarily in exact agreement with absolute thermometers as to their numerical scale rea
Liquid in glassthermometers
. Liquidinglassthermometers are made of sealed glass and contain a fluid, usuallymercuryorred alcohol, whose volume changes relative to its temperature. The liquid expands as the temperature rises, rising in the tube and indicating the temperature.
. Bimetallic stripthermometers include two different metals that are bonded together and expand at different rates as they warm up. Since the two metals expand to different lengths, the bimetallic strip is forced to bend or curl towards the side with a lower coefficient of thermal expansion. The movement of the strip is used to deflect a pointer over a calibrated scale which then indicate temperature to the user. Often, long bimetallic strips are w
. Thermometers utilize a range of physical effects to measure temperature. Temperature sensors are used in a wide variety of scientific and engineering applications, especially measurement systems. Temperature systems are primarily either electrical or mechanical, occasionally inseparable from the system which they control (as in the case of a mercuryinglass thermometer). Thermometers are used in roadways in cold weather climates to help determine
Read the directions
. Read the directions included with the thermometer to understand the beeps associated with the thermometer.Some digital thermometers beep every few seconds to signify that its still reading the temperature, while others have a succession of beeps when the reading is finished.
Turn the thermometer on and make sure the reading is at zero
. Slip the tip of the thermometer into a disposable plastic sleeve. Available at drugstores, these sleeves are usually a onesizefitsall product. Internationally agreed temperature scales are designed to approximate this closely, based on fixed points and interpolating thermometers. The most recent official temperature scale is the International Temperature Scale of 1990. It extends from 0.65 K to approximately 1,358 K .
Take a temperature with a digital thermometer
. Take an axillary temperature under the arm by placing the tip of the thermometer into the hollow of the armpit. Hold the arm across the body until the thermometer beeps. Perform an oral temperature by placing the tip of the thermometer under the tongue and holding it there until the thermometer beeps.
. Read the manufacturers instructions to understand how the thermometer works.Place a disposable cover over the tip of the thermometer, if it wasnt stored with one on. These plastic covers are available at any drugstore. clinical thermometer one used to determine the temperature of the human body.
Clean the thermometer after each use
. Clean the thermometer after each use with an alcohol rub or according to the manufacturers directions.Even when using a disposable sleeve, its best to sanitize the thermometer to reduce the risk of spreading any germs. While an individual thermometer is able to measure degrees of hotness, the readings on two thermometers cannot be compared unless they conform to an agreed scale. Today there is an absolute thermodynamic temperature scale.
Turn the thermometer on and make sure the screen reads zero
. If a saved reading shows, follow the manufacturer instructions to set the thermometer back to zero. Operating principles of thermometers include the thermal expansion of solids or liquids with temperature, or the change in pressure of a gas on heating or cooling. Radiationtype thermometers measure the infrared energy emitted by an object, allowing measurement of temperature without contact.
Pull the ear canal open by gently pulling the ear lobe back and up
. Insert the tip of the thermometer into the ear canal, being careful not to push too far into the ear, and press the button. The reading will be immediate. electronic thermometer a clinical thermometer that uses a sensor based on thermistors, solidstate electronic devices whose electrical characteristics change with temperature. The reading is recorded within seconds, some having a red light or other device to indicate when maximum temperature is
Discard the plastic cover and put a new one on
. Its best to store a tympanic thermometer with a plastic cover on the tip to keep the reading mechanism from getting dirty or damaged. Laboratory thermometers are used in research and scientific applications such as monitoring experiments, maintaining a sterile work environment, calibrating other laboratory instruments, and testing materials.
Laboratory thermometers are devices used to measure temperature
. Laboratory thermometers are devices used to measure temperature. There are many types of lab thermometers such as differential, mechanical, logging, etc. Laboratory thermometers are progressively providing digital reading displays and are inputcapable to computer and software programs for logging purposes. A laboratory thermometer can be used for a number of scientific applications and can be found across nearly all laboratories especially in pha
. This filledsystem thermometer utilizes the vapor pressure of certain stable liquids to measure temperature. The useful portion of any liquidvapor pressure curve is between approximately 15 psia (100 kilopascals absolute) and the critical pressure, that is, the vapor pressure at the critical temperature, which is the highest temperature for a particular liquidvapor system. A nonlinear relationship exists between the temperature and the vapor press
. This device is made of a solid semiconductor with a high temperature coefficient of resistance. The thermistor has a high resistance, in comparison with metallic resistors, and is used as one element in a resistance bridge. Since thermistors are more sensitive to temperature changes than metallic resistors, accurate readings of small changes are possible.