Three Challenges That Arise When Measurement Cannot Be Performed Correctly in Special Environments
In special environments such as vacuum, explosion-proof, and high-temperature environments, conventional measurement methods each have their own limitations on site.
Conventional Measuring Instruments Cannot Be Installed in Special Environments
In vacuum, high-temperature, and explosion-proof areas, general displacement sensors cannot be installed due to outgassing, heat resistance, and explosion-proof certification constraints, making measurement itself impossible. If dimensions and thickness cannot be monitored within the process, variations in vacuum deposition and deviations in rolling thickness cannot be detected until subsequent processes, leading to reduced yield and rework. In special environments, measurement methods with environmentally resistant designs that can be installed on site are the key to quality.
Vacuum Measurements Tend to Rely on Capacitive or Contact Methods
Although capacitive sensors are the main choice in vacuum, they require close installation to the target, are easily affected by material and electrostatic charge, and increase setup work. A configuration where the measuring instrument is brought into the chamber carries risks of maintenance and vacuum loss. Without a method that can measure stably from a distance without contact, dimension and thickness control in vacuum processes becomes dependent on individual skills, and variations in deposition and positioning escape to subsequent processes.
Cannot Measure Close to High-Temperature Targets
On red-hot slabs and high-temperature lines, bringing the measuring instrument close to the target causes failure or drift due to heat, and contact sensors cause deformation and scratches. Relying on sampling and offline measurement because the instrument cannot be brought close means missing dimensional changes due to temperature, weakening the basis for rolling accuracy and quality assurance. In high-temperature environments, a heat-resistant sensor head or a combination of long-range measurement that can measure from a distance is essential.
Measurement Approaches by Environment
Depending on the constraints of vacuum, explosion-proof, and high-temperature environments, compatible heads and long-range measurement are used selectively.
- 1 Vacuum/Ultra-high vacuum – Environment 1. Install a vacuum/heat-resistant head with suppressed outgassing using a dedicated feedthrough. Measure stage positions, robot behavior, and more in a vacuum without contact.
- 2 Explosion-proof area – Environment 2. Measure inside hazardous areas with a Zone 0/Division 1 compatible head. Connector connection simplifies explosion-proof installation work, and total thickness measurement immediately after coating is also possible.
- 3 High temperature (close proximity/heat resistant) – Environment 3. Install a 200°C heat-resistant head in high-temperature environments. Stably measure dimensions, thickness, and displacement even in environments with large temperature changes.
- 4 High temperature (long range/through glass) – Environment 4. For high-temperature targets that cannot be approached, install the long-range LK/LJ Series at a distance. Measure red-hot targets without contact through glass or with a water-cooling jacket.
Comparison of Measurement Methods in Special Environments
Depending on the measurement method, there are significant differences in compatibility with vacuum, explosion-proof, and high-temperature environments, as well as ease of remote installation.
Non-contact / Impact on target
CL-3000 Series (Coaxial laser/non-contact; LK/LJ Series used in combination for high temperatures)
○ Non-contact, no impact
Capacitive type
△ Close installation required
Contact type (micrometers, etc.)
× Risk of contact/deformation
General laser displacement sensors
○ Non-contact
Compatibility with vacuum/ultra-high vacuum
CL-3000 Series (Coaxial laser/non-contact; LK/LJ Series used in combination for high temperatures)
○ Vacuum/heat-resistant head + feedthrough
Capacitive type
△ Affected by proximity/material
Contact type (micrometers, etc.)
× Difficult to configure
General laser displacement sensors
× Standard models not compatible
Compatibility with hazardous areas (Zone 0)
CL-3000 Series (Coaxial laser/non-contact; LK/LJ Series used in combination for high temperatures)
○ Supported with explosion-proof head
Capacitive type
× Generally not compatible
Contact type (micrometers, etc.)
× Generally not compatible
General laser displacement sensors
× Standard models not compatible
Measurement in high-temperature/heat-resistant environments
CL-3000 Series (Coaxial laser/non-contact; LK/LJ Series used in combination for high temperatures)
○ 200°C heat-resistant head + long-range measurement
Capacitive type
△ Affected by heat due to proximity
Contact type (micrometers, etc.)
× Deformation/scratches
General laser displacement sensors
△ Depends on the model
Through glass / Remote installation
CL-3000 Series (Coaxial laser/non-contact; LK/LJ Series used in combination for high temperatures)
○ Supported through glass / at long distances
Capacitive type
× Close proximity required
Contact type (micrometers, etc.)
× Direct contact
General laser displacement sensors
△ Depends on the model
Role (best-suited applications)
CL-3000 Series (Coaxial laser/non-contact; LK/LJ Series used in combination for high temperatures)
◎ Thickness/displacement in vacuum, explosion-proof, and high-temperature environments
Capacitive type
Proximity displacement in vacuum
Contact type (micrometers, etc.)
Dimensions of stationary targets
General laser displacement sensors
Non-contact displacement at room temperature
Why Choose the CL-3000 Series
The CL-3000 Series features coaxial laser non-contact measurement, offering vacuum/heat-resistant heads and explosion-proof heads to achieve non-contact measurement in vacuum, explosion-proof, and high-temperature environments. Unlike capacitive sensors, proximity installation is not required, allowing measurement through glass or from outside a chamber. High-temperature targets that cannot be approached can be measured from a distance using the long-range LK/LJ Series.
CL-3000 Series for Thickness and Displacement Measurement in Harsh Environments
A coaxial laser displacement sensor using the multi-color confocal method. Heads designed for vacuum, explosion-proof, and high-temperature environments can be selected and used for non-contact measurement.
Supports Thickness/Displacement Measurement in Vacuum, Explosion-Proof, and High-Temperature Environments — CL-3000 Series
Confocal Displacement Sensor
This coaxial laser displacement sensor uses the multi-color confocal method to measure thickness and displacement inline and without contact, regardless of the material. The sensor head contains only lenses inside, generating no heat, and a wide range of heads for special environments is available. The vacuum/heat-resistant models (CL-V020/V050) use no organic adhesives to minimize outgassing, supporting ultra-high vacuums and ambient temperatures up to 200°C. The explosion-proof model (CL-S015EX) can be used in Zone 0/Division 1 environments (certified by IECEx, ATEX, and NRTL/ACO), and connector connection via a dedicated feedthrough simplifies explosion-proof installation. If the target is too hot to approach, the LK/LJ Series, which supports long-range installation, can be placed at a distance to measure red-hot targets without contact through glass or a water-cooling jacket. This consolidates vacuum, explosion-proof, and high-temperature environments into a single solution.
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Inquiries about thickness and displacement measurement in harsh environments
Application Examples of Thickness and Displacement Measurement in Harsh Environments
Non-contact measurement is used in special environments, such as vacuum chambers, high-temperature lines, and explosion-proof processes.
Stage Position Measurement Inside Vacuum Chambers
A vacuum/heat-resistant head is installed in the chamber using a dedicated feedthrough. This allows non-contact measurement, such as the home position of a vacuum stage, while maintaining the vacuum.
Film Thickness Measurement in Explosion-Proof Environments
Using a sensor head that complies with technical standards for explosion-proof areas, measurements are performed within explosion-proof environments, such as film coating processes.
Dimension Measurement of High-Temperature Slabs and Red-Hot Targets
High-temperature targets that cannot be approached are measured without contact using the long-range LJ-X8000 Series and a water-cooling jacket. The blue laser stably detects even red-hot targets, performing dimension measurement and appearance inspection simultaneously.
Frequently Asked Questions About Thickness and Displacement Measurement in Environment-Resistant Applications (CL-3000 Series)
Yes, they can. By installing a vacuum/heat-resistant head (CL-V020/V050) with a dedicated feedthrough, the position, thickness, and displacement inside the chamber can be measured without contact, even in ultra-high vacuum environments.
Because the CL-3000 Series uses coaxial laser non-contact measurement, there is no need to approach or contact the target. Measurement is possible from outside the chamber or through glass, reducing the effects of material and static charge, as well as the risk of vacuum loss.
Yes, they can. The explosion-proof head (CL-S015EX) is compatible with Zone 0/Division 1 environments (certified by IECEx, ATEX, and NRTL/ACO), and connector connection using a dedicated feedthrough simplifies explosion-proof installation. This also enables applications such as measuring film thickness immediately after coating.
The vacuum/heat-resistant heads (CL-V020/V050) can withstand ambient temperatures up to 200°C. If the sensor cannot be placed close to the target, the long-range LK/LJ Series can be installed at a distance to measure red-hot targets through a water-cooling jacket or glass.
When gas is released from components in a vacuum, it affects the vacuum level and film deposition quality. The CL-V020/V050 minimizes outgassing to the absolute limit by avoiding the use of organic adhesives inside the head and shipping the heads in degassed packaging after baking.
The LK/LJ Series, which supports long-range installation, is placed at a distance to perform non-contact measurement through a mirror or glass, or in combination with a water-cooling jacket. This allows stable measurement even on red-hot slabs or rolling lines.
- Confocal Displacement Sensor CL-3000 series
Confocal Displacement Sensor
CL-3000 series
