Related Experiment Video
Updated: Jun 23, 2025
08:44
Fabrication and Testing of Photonic Thermometers
Published on: October 24, 2018
5.8K
Johnson Noise Thermometry
Measurement Science & Technology
|June 25, 2024
Summary
Johnson noise thermometry measures thermodynamic temperature using electronic current fluctuations. This technology shows promise for precise measurements from microKelvin to 800 Kelvin and potentially above 2000 Kelvin for industrial use.
Area of Science:
- Physics
- Metrology
- Electrical Engineering
Background:
- Johnson noise thermometers measure thermodynamic temperature via thermally-induced current fluctuations in electrical conductors.
- This technology offers a purely electronic method for temperature determination.
Purpose of the Study:
- To review the current status and future prospects of Johnson noise thermometry (JNT).
- To explore JNT's applications in metrology and industry.
Main Methods:
- Review of foundational principles of Johnson noise thermometry.
- Outline of various techniques and technological advancements enabling JNT.
- Discussion of digital technology's impact on noise thermometry.
Main Results:
- JNT is applicable for high-accuracy measurements from below 1 microKelvin to 800 Kelvin.
- Advancements enable potential industrial applications above 2000 Kelvin.
- JNT is the sole electronic method for thermodynamic temperature measurement.
Conclusions:
- Johnson noise thermometry is a key technology for metrological applications across a wide temperature range.
- Digital advancements are expanding the potential for industrial applications of JNT.
- Noise thermometry is poised for broader adoption in both scientific and industrial settings.
Related Concept Videos
01:22Thermometers and Temperature Scales
5.3K
Any physical property that depends consistently and reproducibly on temperature can be used as the basis of a thermometer. For example, volume increases with temperature for most substances. This property is the basis for the common alcohol thermometer and the original mercury thermometers. Other properties used to measure temperature include electrical resistance, color, and the emission of infrared radiation.
As many physical properties depend on temperature, the variety of thermometers is...
As many physical properties depend on temperature, the variety of thermometers is...
5.3K
01:14Temperature Measurement Sites
1.6K
A thermometer measures body temperature. The common sites for measuring body temperature are the oral cavity, axillary region, temporal artery, and skin surface, such as the forehead, abdomen, and axilla. True core body temperature is assessed in the rectum, tympanic membrane, pulmonary artery, esophagus, and urinary bladder.
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
1.6K
01:14Assessing Body Temperature - Tympanic membrane
576
Assessing tympanic membrane temperature involves using a tympanic membrane thermometer (TMT). Here is a step-by-step guide:
Step 1: Begin by practicing good hand hygiene to prevent the transmission of microorganisms.
Step 2: Turn on the thermometer and wait until the ready sign appears on the screen to ensure accurate measurement.
Step 3: Slide the probe cover in place to prevent cross-contamination.
Step 4: Instruct the patient to tilt their head to the side for comfort and check for cerumen...
Step 1: Begin by practicing good hand hygiene to prevent the transmission of microorganisms.
Step 2: Turn on the thermometer and wait until the ready sign appears on the screen to ensure accurate measurement.
Step 3: Slide the probe cover in place to prevent cross-contamination.
Step 4: Instruct the patient to tilt their head to the side for comfort and check for cerumen...
576
01:22Gas Thermometers and the Kelvin Scale
4.5K
The definition of temperature in terms of molecular motion suggests that there should be a lowest possible temperature, where the average kinetic energy of molecules is zero (or the minimum allowed by quantum mechanics). Experiments confirm the existence of such a temperature, called absolute zero. An absolute temperature scale is one whose zero point is absolute zero. Such scales are convenient in science because several physical quantities, such as the volume of an ideal gas, are directly...
4.5K
01:13Equipments Used to Measure Body Temperature
992
Body temperature can be assessed using various devices and measured in Celsius or Fahrenheit.
Glass-bulb Thermometer:
Glass-bulb thermometers are hollow glass tubes with a bulb tip containing liquid such as ethanol or mercury. Historically, glass bulb mercury thermometers were the standard device to measure body temperature. Today, mercury thermometers are prohibited in many countries due to the hazardous effects of mercury and the risk of exposure if the glass bulb breaks. In general,...
Glass-bulb Thermometer:
Glass-bulb thermometers are hollow glass tubes with a bulb tip containing liquid such as ethanol or mercury. Historically, glass bulb mercury thermometers were the standard device to measure body temperature. Today, mercury thermometers are prohibited in many countries due to the hazardous effects of mercury and the risk of exposure if the glass bulb breaks. In general,...
992
01:11Temperature and Thermal Equilibrium
6.6K
Heat and temperature are essential concepts for everyone every day. The study of heat and temperature is part of an area of physics known as thermodynamics. It is not always easy to distinguish heat and temperature.
The concept of temperature has evolved from the common concepts of hot and cold. The scientific definition of temperature explains more than just our sense of hot and cold. Temperature is operationally defined as the quantity measured with a thermometer. Furthermore, temperature is...
The concept of temperature has evolved from the common concepts of hot and cold. The scientific definition of temperature explains more than just our sense of hot and cold. Temperature is operationally defined as the quantity measured with a thermometer. Furthermore, temperature is...
6.6K