Infrared thermometers are very popular and commonly used throughout many industrial sectors and work environments to measure the surface temperature of any object. These thermometers are very useful and also helps to bring down many accidents, since the rise in temperatures are the initial sign of trouble of many mechanical and electrical equipment. If the temperatures are monitored regularly of major components, it can prevent many disasters and troubles. There are many advantages of IR thermometers over the conventional probe thermometer, the foremost is infrared thermometers are non invasive. With infrared thermometers you can measure the temperature of any object without touching or going close to it. The other benefit is that it measures the temperature very fast. You don’t have to wait for minutes or many seconds to get accurate reading.
There are different types of Infrared thermometers available today in the market. They comes in different size and shape. They are also suitable for different purpose. So if you are going to buy a new infrared thermometers, make a good research and understand your need. Also there are many cheap quality infrared thermometers that does not give accurate reading. Always buy a reliable thermometer that are accurate and also durable, You can check out some top infrared thermometers in UK here. This article will help you in knowing more about IR thermometer and also help you in choosing the right infrared thermometer for your needs.
What is Infrared thermometer
Infrared (IR) thermometers measure reflected infrared light, which just like any light ray is Electromagnetic Radiation, with lower frequency (or longer wavelength) than visible light and can be correlated to a specific surface temperature of the product being measured. As it is the surface of an object that emits infrared, an infrared thermometer will not measure its internal (core) temperature. Infrared radiation, or IR, is just one type of radiation that exists within the electromagnetic spectrum. The laser is just there to show you where you are pointing the device. Anything above absolute zero (-273.15 degrees Celsius or 0 degrees Kelvin) radiates in the infrared. You cannot accurately measure through any covering (glass, polythene, clingfilm etc). Any surface you are measuring must be clean and dust free. Additional types of electromagnetic radiation include microwaves, x-rays and visible light. They work fine with the laser turned off. Even ice cubes, snow, and your refrigerator emit infrared. Air temperature cannot be measured by an infrared thermometer.
The illustration below shows wavelength and frequency of the electromagnetic spectrum. Instead, they are just infrared radiation detectors. Everything constantly gives off thermal radiation because of its temperature, which consists mostly of infrared radiation for everyday temperatures. The distribution of frequencies in the thermal radiation given off depends on the temperature of the object. By measuring the thermal frequency distribution, the thermometer can calculate the temperature.
How Infrared Thermometers Work
You can point the IR thermometer on an ant on your desk, but what you get is an average temperature of the ant and the desk because the Field Of View of the IR thermometer is much larger than the Ant. IR light works like visible light—it can be focused, reflected or absorbed. Infrared thermometers are characterised by specifications including accuracy and angular coverage. Many non-metallic materials such as wood, plastic, rubber, organic materials, rock, or concrete have surfaces that reflect very little, and therefore have high emissivities between 0.8 and 0.95. But, if you can get 10,000 ants on your desk, which can cover the whole FOV of the IR thermometer, then YES, you can measure the body temp of the Ants.
Handheld IR thermometers typically use a lens to focus light from one object onto a detector, called a thermopile. Simpler instruments may have a measurement error of about ±2 °C/±4 °F). The distance-to-spot ratio (D:S) is the ratio of the distance to the measurement surface and the diameter of the temperature measurement area. By contrast, metals especially those with polished or shiny surface have emissivities at around 0.1. The thermopile absorbs the IR radiation and turns it into heat. For instance if the D:S ratio is 12:1, the diameter of the measurement area is one-twelfth of the distance to the object. IR thermometers compensate for this by offering variable options for setting the emissivity factor. The more IR energy, the hotter the thermopile gets. This heat is turned into electricity. The electricity is sent to a detector, which uses it to determine the temperature of whatever the thermometer is pointed at. The more electricity, the hotter the object. The higher the temperature, the more electricity sent to the detector, the higher the reading.
Emissivity is the measure of an object’s ability to emit infrared energy. he accuracy of the following figures is almost impossible to guarantee as the emissivity of a surface will not only alter with regard to texture and colour but also with its actual temperature at the time of measurement. Knowledge of surface emissivity is important both for accurate non-contact temperature measurement and for heat transfer calculations. The emissivity coefficient – ε – for some common materials can be found in the table below. Emitted energy indicates the temperature of the object.
We would recommend, in the first instance, comparing measurements found, with an accurate surface probe or wire probe, and then the Infrared thermometer can be adjusted to match the correct emissivity and used for subsequent measurements. Radiation thermometers detect the thermal radiation emitted by a surface. Note that the emissivity coefficients for some products varies with the temperature. Emissivity can have a value from 0 (shiny mirror) to 1.0 (black body). Most organic, painted, or oxidized surfaces have emissivity values close to 0.95. They are generally calibrated using black body reference sources that have an emissivity as close to 1 as makes no practical difference.
As a guideline the emmisivities below are based on temperature 300 K. When viewing ‘real’ more reflective surfaces, with a lower emissivity, less radiation will be received by the thermometer than from a black body at the same temperature and so the surface will appear colder than it is unless the thermometer reading is adjusted to take into account the material surface emissivity.
Infrared Thermometers Advantages
TempIR gives an almost instantaneous reading, and there is a built in fever alarm to indicate if a temperature is very high. Understanding the difference between contact and non-contact temperature measurements is vitalto health, safety and quality issues in a wide range of industries.Use of thermometers to measure temperature has been around for centuries. The greatest advantage of IR thermometers is the ability to take temperature measurements of hot, hazardous, or hard-to-reach objects without contact. With standard IR meters, measurements can be taken from within a few inches to approx. 10 ft away from the object. Since infrared thermometers can determine the temperature of a target object without physical contact, the measurement system does not contaminate, damage, or interfere with the process being monitored and has many advantages over contact measurement devices. The thermometer can be used again immediately, which is handy if you have two sick children, or if you need to check the reading quickly.
- Temperature is the second most frequently measured physical quantity after time.
- IR thermometers are usually available with lasers, which are used to help the user define the area they are measuring.
- An Infrared Thermometer can be mounted remotely from the hot target, enabling it to operate for long periods with minimal maintenance.
- TempIR stores the previous 32 readings, so it’s easy to check on the progress of the patient.
- Various fields including civil, mechanical, medical, manufacturing, quality control, maintenance etc. depend heavily on accurate temperature measurements.
- Units with Class II lasers use less than 1 mW of power and can take measurements up to 50 ft from the object.
- Another significant advantage is the very fast response time provided by infrared thermometers, typically a temperature measurement can be made within a few thousandths of a second.
Studies show that temporal artery temperature measurement is more accurate than tympanic or axillary temperature recording. It provides important information such as condition of a machine;climate control for refrigerators and air conditioners;help determine if icing conditions exist etc.Accurate temperature monitoring insures that processes are operating consistently under optimum conditions,which results in improved product quality,increased safety,increased productivity, and reduced downtime. Units with Class III a lasers use less than 5 mW of power and can take measurements up to 100 ft away.
Infrared sensors offer the same technology and features as infrared thermometers except they output different signals. Most IR thermometers are limited to a measuring distance of approx. 100 ft due to atmospheric considerations. They can output thermocouple, voltage, or analog signals to displays or controllers. However, even with their limitations, IR thermometers still surpass standard thermometers regarding the distance from the object that is necessary for temperature measurement. 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.