German Dressel sensor Dressel model Dressel price

Dressel sensor pressure sensor for level measurement. The static pressure submersible level transmitter (level gauge) is based on the principle that the static pressure of the measured liquid is proportional to its height. It uses advanced foreign isolated diffused silicon sensitive elements or ceramic capacitive pressure sensitive sensors to convert static pressure into electrical signals, which are then converted into standard electrical signals (typically 4～20mA/15VDC) after temperature compensation and linear correction.

Dressel 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 ruler. 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, classified according to their structural characteristics and application scenarios into direct-receiving readheads (also known as silicon photovoltaic cell readheads, mirror-image readheads, beam-splitter readheads, and metal grating reflective readheads).

Dressel sensor principle

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

Dressel sensor usage precautions

When plugging and unplugging the connector of the linear encoder sensor and the digital readout unit, ensure the power is turned off. Install an external protective cover whenever possible, and promptly remove chips and oil splashed onto the scale to strictly prevent any foreign matter from entering the housing of the linear encoder sensor. Regularly check whether the 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, taking care not to let it splash onto the glass grating etched surface. To ensure the reliability of the linear encoder sensor, clean and wipe the linear encoder scale surface and the index grating surface at regular intervals using an ethanol mixture (50%), keeping the glass linear encoder scale surface clean. The linear encoder sensor is strictly prohibited from being 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 on your own, and never arbitrarily change the relative spacing between the main grating scale and the secondary grating scale. Otherwise, this may compromise the accuracy of the linear encoder sensor and cause relative friction between the main grating scale and the secondary grating scale, damaging the chrome layer and thus the grating lines, resulting in scrapping of the linear encoder scale. Take care to prevent oil stains and water from contaminating the linear encoder scale surface, which could disrupt the distribution of the grating lines and cause measurement errors. The linear encoder sensor should be operated in environments with severe corrosive effects as little as possible, to avoid corroding the grating chrome layer and the linear encoder scale surface, thereby degrading the quality of the linear encoder scale.

Weidou Intelligent Technology specializes in selling German Dressel sensors, Dressel proximity sensors, Dressel distance sensors, Dressel vision sensors, Dressel displacement sensors, Dressel torque sensors, Dressel speed sensors, Dressel photoelectric sensors, Dressel position sensors, Dressel angle sensors, Dressel tactile sensors, Dressel temperature sensors, Dressel pressure sensors, Dressel flow sensors, Dressel level sensors, Dressel motion sensors, Dressel process sensors. Original imports from Germany. Welcome inquiries and orders from customers.