German NORELLAGG sensor NORELLAGG model NORELLAGG price

NORELLAGG sensors are measurement feedback devices that operate based on the optical principle of gratings. Grating scales are frequently used in the closed-loop servo systems of CNC machine tools and can be used to detect linear or angular displacement. The measurement output signal is a digital pulse, characterized by a large detection range, high detection accuracy, and fast response speed. For example, in CNC machine tools, they are often used to detect the coordinates of tools and workpieces to observe and track tool path errors, thereby compensating for tool motion errors. Grating scales are classified according to different manufacturing methods and optical principles into transmission gratings and reflection gratings.

NORELLAGG sensor structure

It consists of two parts: the scale grating and the grating readhead. The figure on the right shows the structure of the grating scale. The key part of the grating detection device is the grating readhead, which consists of a light source, condensing lens, index grating, photoelectric elements, and adjustment mechanisms. There are many structural forms of grating readheads, which are divided into direct-receiving readheads (also known as silicon photovoltaic cell readheads, mirror-image readheads, beam-splitter readheads, and metal grating reflective readheads) based on their structural characteristics and application scenarios.

NORELLAGG sensor principle

The essence of a grating displacement sensor is to measure position using the grating pitch as a standard ruler. High-resolution grating scales are generally expensive and difficult to manufacture. To improve system resolution, Moiré fringes need to be subdivided; grating scale sensor systems mostly use electronic subdivision methods. When two gratings overlap with a slight inclination angle, Moiré fringes are generated in a direction roughly perpendicular to the grating lines. As the grating moves, the Moiré fringes also move up and down. This converts the measurement of the grating pitch into the measurement of the number of Moiré fringes. Within the width of one Moiré fringe, placing 4 photoelectric devices at certain intervals can achieve electronic subdivision and direction determination functions. For example, for a grating scale with 50 line pairs/mm, its grating pitch is 0.02mm. If four-fold subdivision is used, counting pulses with a resolution of 5μm can be obtained, which achieves very high precision in general industrial measurement and control. Since displacement is a vector, both its magnitude and direction must be detected; therefore, at least two photoelectric signals with different phases are required. To eliminate common-mode interference, DC components, and even harmonics, differential amplifiers composed of low-drift operational amplifiers are usually used. The 4 photoelectric signals obtained from 4 photosensitive devices are sent to the input terminals of 2 differential amplifiers respectively. The two signals output from the differential amplifiers have a phase difference of π/2. To obtain direction determination and counting pulses, these two signals need to be shaped, first into square waves with a duty cycle of 1:1. Then, by comparing the phase of the square waves, the movement direction of the grating scale can be determined. By counting the square wave pulses, the displacement and speed of the grating scale can be obtained.

NORELLAGG sensor usage precautions

Power off before plugging or unplugging the connector between the linear encoder sensor and the digital readout. Install a protective cover whenever possible, promptly remove chips and oil that splash onto the scale, and strictly prevent any foreign matter from entering the linear encoder sensor housing. Regularly check whether all mounting and connection screws are loose. To extend the service life of the dust-proof sealing strip, apply a thin, even layer of silicone oil to the sealing strip; take care not to let it splash onto the glass grating etched surface. To ensure reliable operation of the linear encoder sensor, periodically clean and wipe the linear encoder scale surface and the index grating surface with an ethanol mixture (50%) to keep the glass linear encoder scale surface clean. The linear encoder sensor must not be subjected to severe vibration or impact, as this may damage the linear encoder scale; if the linear encoder scale breaks, the linear encoder sensor will fail. Do not disassemble the linear encoder sensor yourself, and never arbitrarily change the relative spacing between the main scale and the secondary scale; otherwise, you may compromise the accuracy of the linear encoder sensor and cause relative friction between the main scale and the secondary scale, damaging the chrome layer and thus the grating lines, which will render the linear encoder scale unusable. Take care to prevent oil contamination and water from polluting the linear encoder scale surface, as this can disrupt the distribution of the grating lines and cause measurement errors. Avoid operating the linear encoder sensor in environments with severe corrosive effects, to prevent corrosion of the grating chrome layer and the linear encoder scale surface, which would degrade the quality of the linear encoder scale.

Weidou Intelligent Technology professionally sells German NORELLAGG sensors, NORELLAGG proximity sensors, NORELLAGG distance sensors, NORELLAGG vision sensors, NORELLAGG displacement sensors, NORELLAGG load cells, NORELLAGG speed sensors, NORELLAGG photoelectric sensors, NORELLAGG position sensors, NORELLAGG angle sensors, NORELLAGG tactile sensors, NORELLAGG temperature sensors, NORELLAGG pressure sensors, NORELLAGG flow sensors, NORELLAGG level sensors, NORELLAGG motion sensors, NORELLAGG process sensors. Original imports from Germany. Welcome customers to inquire and order.