Temperature: Digital and Glass Thermometers (2024)

FAQs

Are glass thermometers more accurate than digital? ›

Both laboratory and clinical studies show that there is no significant difference in the average accuracy of the two types of thermometers, however there is a greater fluctuation of readings of temperature when using electronic thermometers.

So we can verify, yes a thermometer can give you a false reading even if you follow all the instructions. Just be on the lookout for the obvious red flags. Both Lipschitz and Lumsden also suggest replacing your thermometer every few years.

A thermometer is an instrument that measures temperature. It can measure the temperature of a solid such as food, a liquid such as water, or a gas such as air. The three most common units of measurement for temperature are Celsius, Fahrenheit, and kelvin. The Celsius scale is part of the metric system.

The accuracy of a typical glass thermometer is ±1 scale division. These are available in partial immersion or total immersion types and typically have to be considerably longer to achieve the same specifications as a mercury thermometer.

The small silvery ball in a mercury thermometer can be dangerous if the glass breaks and the mercury is not cleaned up properly. The mercury will evaporate and can contaminate the surrounding air and become toxic to humans and wildlife. Each thermometer contains about . 5-1.5 grams of mercury.

Disadvantages. Liquid in glass thermometers tend to be fragile and hence easily broken, can only be used where the liquid column is visible, cannot be used for surface temperature measurements, cannot be read from a distance and are unsuitable for high temperature measurements.

The ice bath test is the easiest way to test a thermometer for accuracy, assuming your thermometer will display temperatures of 32°F or less. The advantage of this method is that an accurate thermometer will always read 32°F in a properly made ice bath regardless of altitude or atmospheric pressure.

Normal body temperature ranges from 97.5°F to 99.5°F (36.4°C to 37.4°C). It tends to be lower in the morning and higher in the evening. Most healthcare providers consider a fever to be 100.4°F (38°C) or higher. A person with a temperature of 99.6°F to 100.3°F has a low-grade fever.

Insert the thermometer stem at least an inch deep in the ice water without letting the stem touch the glass. Wait for the thermometer to register; this usually takes a minute or less. The thermometer is accurate if it registers 32° F or 0° C.

How do we measure temperature in Short answer? ›

Temperature is a measure of the degree of hotness of an object. Thermometer is a device used for measuring temperature. Clinical thermometer is used to measure our body temperature. The range of this thermometer is from 35°C to 42°C.

Leave the thermometer in place for 2-4 minutes.

If you're using a rectal thermometer, 2-3 minutes is enough time. If you're taking a temperature in the mouth or under the armpit, leave the thermometer in place for 3-4 minutes. Try not to shake the thermometer as you pull it out, as this could affect the reading.

Mercury thermometers

Mercury-in-glass thermometers haven't been used in hospitals for some years and are generally no longer available to buy. They can break, releasing small shards of glass and highly poisonous mercury.

Digital thermometers are the most accurate way to measure body temperature. There are many types, including oral, rectal, and forehead, plus many that are multifunctional.

The time-honored mercury thermometer is being phased out (because of environmental concerns), replaced by electronic thermometers with thermistors (oral, rectal, and axillary measurements) and infrared thermometers (tympanic or forehead measurements).

Are mercury glass thermometers safe to use? You should not use a mercury glass thermometer. These readings tend to be less accurate and if the glass breaks and mercury is released, it can poison you. Additionally, fever strips are not recommended, as they are often inaccurate.

Rectal. The thermometer is placed in the child's bottom. It is thought to be the most accurate temperature.

The oldest thermometers used are mercury in glass. Newer thermometers include non-mercury liquids in glass and digital and electronic devices that use sensors to measure temperature. Thermometers that check body temperature in the ear, across the forehead, or have a digital display do not contain mercury.

What is range of fever? ›

An adult probably has a fever when the temperature is above 99°F to 99.5°F (37.2°C to 37.5°C), depending on the time of day.

Rectal temps are the most accurate. Forehead temps are the next most accurate. Oral and ear temps are also accurate if done properly. Temps done in the armpit are the least accurate.

Low-grade fever

The medical community generally defines a fever as a body temperature above 100.4 degrees Fahrenheit. A body temp between 100.4 and 102.2 degree is usually considered a low-grade fever. “If the temperature is not high, it doesn't necessarily need to be treated with medication,” Dr. Joseph said.

Temperatures taken from the armpit are usually the least accurate. For older children and adults, oral readings are usually accurate — as long as the mouth is closed while the thermometer is in place.

The following thermometer readings generally indicate a fever: Rectal, ear or temporal artery temperature of 100.4 (38 C) or higher. Oral temperature of 100 F (37.8 C) or higher. Armpit temperature of 99 F (37.2 C) or higher.

Symptoms may appear 2-14 days after exposure to the virus. People with these symptoms or combinations of symptoms may have COVID-19: Fever greater than 99.9F or chills.

A fever can be a sign of other infections or non-infectious conditions, not just COVID-19. For COVID-19, a fever is considered 100.0 degrees Fahrenheit or above for most people, and 99.6 degrees Fahrenheit and above for anyone 65 years and older or people who are immunosuppressed.

Should I add a degree to oral (under the tongue) and axillary (under the arm) readings? Yes, for the most accuracy. Rectal temperatures are considered most accurate indication of the body's temperature. Oral and axillary temperature readings are about ½° to 1°F (.

You have held the device in your hand too long. Put the device on the table in the room where the measurement is taking place and let it cool down first. Your room temperature is too low or too high. Use your thermometer at temperatures between 10.0 °C/ 50.0 °F and 40.0 °C/ 104.0 °F.

How do you read a glass thermometer? ›

The long lines on the thermometer are one degree. Each little line is . 2 degrees. All glass thermometers are marked with an arrow which points to 98.6 (Considered to be the normal adult temperature).

Celsius, Fahrenheit and Kelvin are the three common temperature scales.

Measuring body temperature is very important in medicine. A number of diseases are characterised by a change in body temperature. With other illnesses, the course of the disease can be followed by measuring body temperature. This allows the doctor to analyse the effectiveness of treatments based on body temperatures.

Temperature exerts a major influence on biological activity and growth. Temperature governs the kinds of organisms that can live in rivers and lakes. Fish, insects, zooplankton, phytoplankton, and other aquatic species all have a preferred temperature range.

Temperature is a measure of the degree of hotness of a body. The SI unit of temperature is kelvin (K). But temperature is also measured in celcius (°C) or fahrenheit (°F) scales. The instrument used to measure temperature is called a thermometer.

Temperature is the measure of hotness or coldness expressed in terms of any of several scales, including Fahrenheit and Celsius. Temperature indicates the direction in which heat energy will spontaneously flow—i.e., from a hotter body (one at a higher temperature) to a colder body (one at a lower temperature).

There are three temperature scales in use today, Fahrenheit, Celsius and Kelvin.

Here, we will discuss the two types of thermometers, namely, clinical thermometers and laboratory thermometers.

Shake the thermometer so that the mercury inside goes below 36°C (96.8°F). Place the tip of the thermometer in the centre of the armpit. Make sure your child's arm is tucked snugly against her body. Leave the thermometer in place for at least 4 minutes.

When taking an oral temperature, shake down the glass mercury thermometer to 96°F (35°C) or below. This procedure is not needed for digital thermometers.

When should u shake a glass thermometer? ›

(1) If the thermometer reading is below 94ºF (34.4º C), you have shaken down the thermometer sufficiently. (2) If the thermometer reads 94º F (34.4º C) or above, continue to shake down the thermometer until a desired reading is shown.

Both laboratory and clinical studies show that there is no significant difference in the average accuracy of the two types of thermometers, however there is a greater fluctuation of readings of temperature when using electronic thermometers.

A digital thermometer is simple and convenient to use. It gives faster results than a mercury thermometer which usually takes time to heat up. It is safer as it doesn't contain any harmful chemicals. It gives more precise results than a mercury thermometer.

A liquid-in-glass thermometer is widely used due to its accuracy for the temperature range -200 to 600°C. Compared to other thermometers, it is simple and no other equipment beyond the human eye is required. The LIG thermometer is one of the earliest thermometers. It has been used in medicine, metrology and industry.

The Best Thermometers for Kids and Adults

If you're looking for a digital oral/rectal/armpit stick thermometer, our pick is the Vicks ComfortFlex. If you want an in-ear thermometer, we recommend the Equate Infrared In-Ear Digital Thermometer.

Benefits. Tympanic thermometers provide fast and accurate readings and may be preferable to oral or rectal thermometers, especially in children.

TRITEMP™ thermometers are an essential piece of equipment in hospitals but they can be used in a wider range of medical settings, including dentists, care homes and doctor surgeries.

Rectal temperatures are considered most accurate indication of the body's temperature. Oral and axillary temperature readings are about ½° to 1°F (. 3°C to . 6°C) below rectal.

Rectal temps are the most accurate. Forehead temps are the next most accurate. Oral and ear temps are also accurate if done properly. Temps done in the armpit are the least accurate.

Consider seeing a doctor if:

Fever lasts longer than three to five days. Fever doesn't respond to fever-reducing medications, such as acetaminophen or ibuprofen (Tylenol or Advil) Other symptoms include confusion, neck stiffness or sensitivity to light.

Where should you put a thermometer? ›

How accurate are they? For general use at home, forehead thermometers will give an idea of whether or not an individual has a fever. However, according to a 2020 study, forehead thermometers are less accurate than other methods of reading temperature, such as oral, rectal, or tympanic (ear) temperature readings.

Armpit temperature

But armpit temperatures are typically less accurate than oral temperatures. Turn on the digital thermometer. Place the thermometer under your armpit, making sure it touches skin, not clothing. Hold the thermometer tightly in place until you hear the thermometer beep indicating it's done.

Call your health care provider if your temperature is 103 F (39.4 C) or higher. Seek immediate medical attention if any of these signs or symptoms accompanies a fever: Severe headache. Rash.

The National Institute of Standards and Technology (NIST), which is working with EPA on this effort, announced on February 2, 2011 that it will no longer calibrate mercury-in-glass thermometers for traceability purposes beginning on March 1, 2011 .

Digital thermometers provide faster results

Digital thermometers provide fast results as opposed to mercury thermometers whose readings are slower to realize because you have to wait for the mercury to heat and then slowly rise to display the temperature.