Confocal Fiber Displacement Sensor
last update: January 7, 2019
Omron's, unique, white light confocal displacement sensor provides higher resolution measurements of angled or curved and shiny surfaces than traditional laser displacement sensors.
The ZW-8000 Series can measure the top and bottom surfaces of a thin transparent sheet or film by separating the light reflected from both surfaces, which is difficult with conventional laser displacement sensors.
Thanks to its very small spot diameter, the ZW-8000 Series can measure targets on minute objects extremely precisely, which is impossible with a conventional laser displacement sensor with a large spot diameter.
*1. Typical value of the ZW-S8010/ZW-S7010/ZW-S5010 Sensor Heads.
*2. Typical value of the ZW-S8010 Sensor Heads when transparent objects with refractive index of 1.5 are measured.
*3. Typical value of the ZW-S8010 Sensor Heads
Note: The ZW-5000 standard type is available for measurements with standard precision and speed.
Using conventional sensors, the measurement accuracy can be achieved by increasing the averaging times, but downside is that this lowers the profile reproduction accuracy. The ZW-7000 acquires a sharp profile by sampling as fast as 20 μs without averaging, solving this issue.
Our white light confocal displacement sensors can provide accurate flatness measurement by tracing an object once without being affected by its excessive reflection, the sensor head direction, nor the material hairline direction, which are difficult to track with a conventional laser displacement sensor.
*4. Please ask Omron sales representative for product data for other than the ZW-S7030.
*5. Objects with machining marks or hairline pattern
*6. ZW-S7020.
*7. Please ask Omron sales representative for product data for other than the ZW-S7020.
Note: All measurement graphs represent typical examples. Measurement may be affected by the shape or material of the object being measured.
Before final installation, test the sensor required for the application to validate that the desired measurements have been obtained.
The continued evolution of products as they have become thinner, more curved, and more compact has meant that the inspection process has also become more diffcult, and this has necessitated visualization and assembly control in the upstream assembly process.
In response to this, Omron has developed a lineup including both square-shaped type sensor heads with long measurement distance, and ultra-small pen-shaped type (straight or right angle) sensor heads that can be installed in narrow spaces.
Measuring range
7±0.3 mm/10±0.7 mm
Linearity ±0.3 m
Weight*1 approx. 27 g
Note: Typical values
Measuring range
7±0.3 mm/10±0.7 mm
Linearity ±0.45 m
Weight*1 approx. 31 g
Note: Typical values
Measuring range
10±0.5 mm/20±1 mm/30±2 mm/40±3 mm *2
Linearity ±0.3 m
Weight*1 approx. 170 g
Note: Typical values
*1. ZW-8000/ZW-7000 Series with 0.3 m fiber cable
*2. The 40 mm type is only available for the ZW-7000 Series.
A conventional laser displacement sensor measures the height of an object based on the position of the spot on the receiver.
The machine requires an extra step to rotate the sensor according to the object shape or moving direction.
Our white light confocal displacement sensor can measure from the same installation position while moving in any direction, with no restriction on installation direction.
The controller connects to the sensor head through a 3 mm diameter flexible fiber cable.
The cable has cleared a bending test consisting of 3,000,000 repetitions*2 for reliable application on moving parts.
*2. Omron's bending test condition: 3,000,000 bends to a 20 mm bending radius
No preamplifiers or optical parts are used in the fiber cable, which makes it easy to route the cable through a cable carrier or protective conduit for moving measurements.
A 30-m extension fiber cable can be used to extend the distance to up to 32 m, supporting a flexible wiring in a large machine.
The compact sensor controller, which integrates the optical unit including the light source and spectroscope, can be mounted on a DIN track, saving space in a control panel.
The fanless structure can be used in cleanrooms for manufacturing semiconductors and electronic components.
Space restrictions prevent side-by-side installation of many traditional laser displacement sensors. The pen-shaped straight sensor heads can be installed close together to obtain multiple measurements at once, instead of measuring one at a time, thus reducing measurement time.
With a traditional laser displacement sensor, the measurement position and spot size vary with the height. This means there are times when the position cannot be measured with high resolution due to warping and inclination. With a white light confocal displacement sensor, the measurement point remains the same at any position in the measuring range so that precise measurements can always be made.
When a traditional laser displacement sensor measures the inside of a narrow tube or the height of a small depression, the wall often obstructs the reflected light, and the orientation of the sensor and object must be adjusted many times. A white light confocal displacement sensor can measure the points in narrow spaces or small objects, without changing its installation orientation, because the emitted light and reflected light are positioned along the same axis.
The sensor head contains no electronic parts and indicators that generate noise and heat.
The sensor head design maintains stable operation in installations with electronic or magnetic noise.
Devices in close proximity and measurement values are not affected by noise or heat from the sensor head.
The ZW Series measures up to 10 points to minimize measurement errors. *1
Even when the sensor head is installed at an angle or measures objects through glass, stable measurements can still be achieved, which is difficult with conventional 2-point scaling.
*1. Supported on ZW-8000 Series
A white light source *2 eliminates the need for safety measures around the machine and safe use training for workers that are required for a laser light source.
When a laser displacement sensor was used, a shield around the machine for safety was required and workers had to be trained for safe use.
*2. The ZW-8000 Series is categorized as Class 1
The sensor controller is compatible with sensor heads, which enables quick replacement and saves costs. Each sensor head has its own calibration ROM that is used to load calibration values into the sensor controller, providing compatibility and high-precision measurements.
When measuring objects with multiple layers, the white light confocal displacement sensor can stably measure target edges even if the object rattles and certain of the edges cannot be measured.
last update: January 7, 2019