Chapter 1
Basics of radiation thermometer
What is the measurement principle of radiation thermometer?
Every object emits infrared energy corresponding to its temperature. radiation thermometer collects this infrared energy using optics and converts it into an electrical signal using detector to determine the temperature.
A typical radiation thermometer the surface temperature of the object being measured.
In models equipped with laser aiming, the laser is primarily used to indicate the measurement location.
Let's take a closer look at the measurement principle of radiation thermometer.
What is emissivity?
emissivity (ε) is a coefficient that represents the degree of infrared energy emitted by an object's surface. In radiation thermometer, it is important to set the appropriate emissivity for the object being measured.
emissivity varies depending on the material and condition of the surface. Even with the same material, it can change depending on surface conditions such as oxidation, coating, and roughness.
What should I do if I don't know emissivity?
First, determine emissivity based on the material and surface condition of the object. In actual measurements, you can also verify the set value by comparing it with a contact thermometer.
Another method involves creating a reference surface using tape or paint with known emissivity and then comparing the results.
Does radiation thermometer only measure surface temperature?
Conventional radiation thermometer can only measure surface temperature non-contact. If you want to check the internal temperature, you should consider contact thermometers such as thermocouples or resistance thermometer.
What is the difference between radiation thermometer and a thermograph?
radiation thermometer are primarily intended to measure the temperature of a specific point or a small area. Thermography, on the other hand, allows us to visualize the temperature distribution as an image.
If you want to measure the temperature at a single point radiation thermometer is suitable, while a thermographic camera is more appropriate if you want to check for temperature variations across an entire surface.
Are you measuring the temperature with a laser?
Temperature measurement itself is performed using infrared energy. In models equipped with a laser, the laser is used as a sight to confirm the measurement location.
What is the D:S ratio?
The D:S ratio is an index that shows the relationship between the measurement distance (Distance) and the measurement spot diameter (Spot).
The further the measurement distance, the larger the measurement area becomes relative to the object. It is important to measure from a position where the measurement spot is sufficiently smaller than the object.
What happens if the spot is larger than the object being measured?
If background elements other than the object being measured are present within the measurement area, the measurement may be affected by the temperature of the background.
The basic principle is to take measurements from a distance where the object being measured is sufficiently contained within the spot.
Can you measure it through glass?
Conventional radiation thermometer may not be able to accurately measure the temperature of an object seen through glass, because the glass itself can affect the reading.
When taking measurements through glass, it is necessary to consider equipment that is suitable for the object, the type of glass, and the wavelength used.
Chapter 2
How to use radiation thermometer correctly
How far away should I measure it?
Check the D:S ratio and measurement field of view described in the instruction manual, and take measurements at a distance where the object to be measured is sufficiently within the measurement spot.
How can we accurately measure moving objects?
When measuring moving objects, the measured value may vary depending on the measurement position and the size of the object.
Position the camera to capture the target object effectively, and utilize features such as peak hold as needed.
How to avoid the effects of reflection?
Mirror-like or glossy surfaces may reflect infrared radiation from the surroundings.
The influence of disturbance is minimized by positioning the device at an angle where high-temperature objects are not within the measurement field of view, or by using shielding plates.
Do I need to change emissivity every time?
If you are measuring the same material and surface condition, there is no need to change the settings each time.
If the material or surface condition changes, check the appropriate emissivity setting.
Can I save the data?
Depending on the model, data storage options include internal memory and output to external devices. Select the appropriate model after confirming the required number of recording points, storage method, and communication method.
Chapter 3
Things that can be measured and things that are difficult to measure
Can it measure mirror-finish metals and aluminum?
Mirror-finish metals and aluminum, for example, can have low emissivity and are therefore susceptible to the effects of reflecting infrared radiation from their surroundings.
Methods for creating a reference surface include using blackbody tape or black paint, or considering radiation thermometer with a wavelength suitable for the target.
Can it measure liquids, oils, and molten materials?
Measurements can be taken if the surface is visible, but measurements may become unstable due to waves, bubbles, or splashes.
It is important to take measurements from the most stable position possible and under the same conditions.
Can it be used on food and cooking utensils?
It can be used to control the surface temperature of griddles, oil, cooking utensils, etc.
For checking the internal temperature of food, please use an appropriate measurement method such as a contact thermometer.
Can it be used to measure a person's body temperature?
Industrial radiation thermometer have different uses than medical thermometers.
For medical and clinical applications, please use medical devices that are suitable for that specific purpose.
Can it be used in high-temperature furnaces or hazardous locations?
In high-temperature furnaces and hazardous locations, specialized models and accessories suited to the operating environment may be required.
Please check specifications of the equipment you will be using, including explosion proof certification, heat resistance requirements, and installation methods.
Chapter 4
Temperature measurements vary depending on the environment.
What about environments with a lot of wind, steam, smoke, and dust?
If there is steam, smoke, dust, etc. between the object being measured and radiation thermometer, infrared rays may absorption or scattered, which can cause measurement errors.
Choose a position with the clearest possible view, and also check the condition of the lenses and protective windows.
What if there is strong sunlight or radiant heat from a furnace?
Infrared radiation emitted from surrounding high-temperature surfaces may reflect off the object and affect the measurement results.
We will consider measures such as changing the measurement angle, shielding, and not including high-temperature objects in the background.
Are ambient temperature and warm-up important?
Each radiation thermometer has its own operating temperature range. If the temperature environment changes rapidly, it is important to wait until the device has acclimatized to the environment before taking measurements.
Will dirt or dew condensation on the lens or protective window be considered within the margin of error?
If infrared rays are blocked by dirt or dew condensation, accurate measurements may not be possible.
Please clean and inspect the product according to the instruction manual.
Chapter 5
Checkpoints when you can't measure the correct temperature
If the temperature reading is incorrect, don't immediately suspect equipment malfunction; instead, check each measurement condition one by one.
1. Check if anything other than the target is in field of view.
If background or surrounding objects are included within the measurement area, their temperature may affect the measurement results.
2. Is emissivity correct?
Setting emissivity inappropriately for the material or surface condition can lead to significant measurement errors.
3. Check for any effects from reflections.
On surfaces like mirrored metals, reflections from surrounding heat sources can affect the measurement results.
4. Check for steam, dust, and smoke.
Check that no material between the object being measured and the equipment is interfering with the transmission of infrared radiation.
5. Check if the lens is dirty.
Dirt on the focusing lens or protective window can cause measurement errors.
emissivity, field of view, disturbance, and lens contamination are some of the key points to check to ensure accurate measurements with radiation thermometer.
See FAQs for when the correct temperature cannot be measured.
Chapter 6
Inspection and calibration of radiation thermometer
Is there a way to check radiation thermometer?
For routine checks, comparing the temperature to a stable reference temperature is helpful.
Chino's FAQ also introduces a simple method for checking the indicator using ice water.
What is verification using blackbody tape?
This method involves using blackbody tape or paint with known emissivity as a reference surface to check the settings and measurement status of radiation thermometer.
Even when using it for routine inspections, please check specifications of the tape and paint used, as well as the measurement conditions.
How do you determine the calibration cycle for radiation thermometer?
Calibration cycles are not determined by a fixed number of years, but rather by considering factors such as frequency of use, operating environment, required accuracy, past calibration results, and the impact of deviations in measured values.
What is blackbody (reference radiation source)?
One method of calibrating radiation thermometer involves using a reference radiation source, such as blackbody furnace, which has a known temperature and a surface with high emissivity, for comparison.
What are the differences between JCSS calibration, general calibration, and Chino calibration?
JCSS calibration is a calibration performed within the scope registration and accredited under the JCSS system based on the Measurement Law.
General calibration is a common term referring to calibration that does not adhere to the JCSS framework. Chino offers "Chino Calibration" based on its own standards.
Let's look at the differences between JCSS calibration, general calibration, and Chino calibration.
Chapter 7
Things you should know about safety and standards
What are your thoughts on the safety of lasers?
Laser-guided radiation thermometer vary in laser class and specifications depending on the model.
Please follow the safety precautions described in the instruction manual for the equipment you are using, such as not shining the light directly into your eyes or pointing it at a mirror.
Laser products are subject to standards such as IEC 60825-1 and JIS C 6802.
Can it be used for medical purposes?
Industrial radiation thermometer and medical thermometers differ in their intended use and required specifications.
For clinical body temperature assessment, please use medical devices appropriate for the intended purpose.
Where can I find information about water resistance, dust proof, and drop resistance?
IP rating and drop resistance performance can be found in the product specifications.
IP ratings are protection ratings based on IEC 60529.
Chapter 8
How to Choose radiation thermometer
Choosing radiation thermometer based solely on its temperature range may not be suitable for real-world applications. The selection process should take into account factors such as the object being measured, distance, material, environment, and required data.
| Selection item | Confirm |
|---|---|
| What to measure | Metals, resins, food, liquids, glass, high-temperature objects, etc. |
| Measurement temperature range | Does the actual temperature being measured fall within the instrument's measurement range? |
| Required accuracy | Precision required for applications such as process control, quality assurance, and reference measurement. |
| D:S ratio/measurement distance | Can a sufficient field of view be secured considering the size of the object and the distance to the equipment? |
| emissivity | Is it possible to set emissivity of the object, and is it unaffected by the surface condition? |
| wavelength | Are there different wavelength methods suitable for different objects, such as metals? |
| Landline/Mobile | On-site inspection or permanent installation on the equipment? |
| Recording and communication | Whether data storage, external output, and PC/smartphone connectivity are necessary. |
| special environment | Can it withstand high temperatures, dust, steam, and explosion proof? |
If you're unsure which to choose
Chino offers radiation thermometer to suit various applications, from portable to stationary models, and from general-purpose to high-temperature, high-speed, and two-color types.
View product and selection information for radiation thermometer
Quick information
Checklist for when you're unsure
- What temperature are you measuring?
- Is surface temperature sufficient?
- Do you know the material and emissivity of the object?
- Are the size of the object and the measurement distance appropriate?
- Are there any reflective, high-temperature objects nearby?
- Are there any steam, smoke, or dust particles in the measurement path?
- Does it meet the required temperature range and accuracy?
- Which is more suitable, a fixed or portable type?
- Is recording/communication necessary?
- Do you need calibration or a certificate?
I would like to consult about the selection and measurement methods of radiation thermometer
You can choose radiation thermometer that suits your application based on factors such as the object to be measured, temperature range, measurement distance, material, operating environment, and whether recording and communication are required.
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