German SELLA SRL sensors, SELLA SRL models, SELLA SRL prices

SELLA SRL pressure sensors for level measurement. Submersible static pressure level transmitters (level gauges) operate on the principle that the static pressure of the measured liquid is proportional to its height. They use advanced imported isolated diffused silicon sensitive elements or ceramic capacitive pressure sensitive sensors to convert static pressure into electrical signals. These signals undergo temperature compensation and linear correction to become standard electrical signals (typically 4 to 20mA/15VDC).

SELLA SRL sensor classification

1) Laser speed measurement: With the rise of precision manufacturing and the need for cost savings, non-contact speed sensors are gradually replacing contact speed sensors. The most common and high-precision non-contact laser speed sensors currently on the market are ZLS-Px aberration speed sensors. Aberration speed sensors have two ports: one emission port that emits a LED light source, and one high-speed imaging port that achieves CCD area high-speed imaging comparison. By comparing images at two points in time within an extremely short period, the distance moved by the object is determined. Combined with internal algorithms, the sensor outputs the object's speed in real time. As shown in the figure: (1) LED light emission port, (2) camera reception port, (3), (4) terminal blocks, (5) mounting screw holes. (1) The LED light emission port directs laser onto the measured object; after reflection, it reaches the (2) camera reception port. Upon receiving the signal, it is transmitted to the signal processor, which calculates the speed via algorithms. ZLS-Px aberration speed sensors can simultaneously measure speed and length in two directions. They not only detect whether the measured object has stopped but also determine its direction of motion. Mount the sensor on a stable bracket to ensure that the rotation of the object does not generate excessive vibration, thereby allowing measurement of the rotational angle and speed of the rotating object. 2) Radar speed measurement: Traditional speed measurement mostly involves rotary motion speed and linear motion speed. However, industrial automation often requires irregular speed measurements, such as athlete speed, traffic vehicle speed, and golf ball speed. Radar speed sensors can meet these requirements.

SELLA SRL sensor principles

Transmissive speed sensors consist of a slotted or notched disk, a light source, and a phototube. When the disk rotates with the measured shaft, light passes through the holes or notches to illuminate the phototube. When illuminated, the phototube's reverse resistance drops significantly, outputting an electrical pulse signal. When the disk blocks the light source, the phototube's reverse resistance becomes very high, and no signal is output. Thus, the rotational speed of the measured shaft can be determined based on the number of holes or notches on the disk. The usual number of disk holes or notches is unclear in the source, so the photoelectric converter outputs 60 pulse signals per revolution of the measured shaft. If the time base signal of the electronic counter is set to 1s, the rotational speed of the measured shaft can be read directly. The principle of reflective speed sensors is similar to transmissive ones, converting changes in received light into electrical signals via a phototube. However, they obtain pulse signals through light reflection, typically by attaching reflective material to the measurement area of the measured shaft to create a reflective surface. Common reflective materials include specialized speed-measuring reflective tape; aluminum foil or other reflective materials can also be used. Sometimes, white paint is applied to the measurement area as a reflective surface. The emitter and reflective surface must be properly configured, typically with a distance of 5-15M between them. When the measured shaft rotates, the photoelectric element receives pulsed light and outputs corresponding electrical signals to an electronic counter, thereby measuring the shaft's rotational speed. The output waveform of photoelectric speed sensors is relatively regular, close to a standard square wave, with almost no interference signals. However, vibration in transmissive types can reduce the light source's lifespan, making them unsuitable for high-vibration environments. Reflective types have no mechanical connection with the measured shaft and are easy to use.

SELLA SRL sensor industry applications

1) Modern vehicles are generally equipped with engine control, autonomous driving, ABS, TRC, automatic door locking, active suspension, guidance systems, electronic instruments, and other devices, All these devices require the vehicle speed signal. Therefore, The accuracy and stability of the output signal from the vehicle speed sensor will have a significant impact on these control units. Vehicle speed sensors mostly adopt a Hall-effect structure, A Hall speed sensor is a magnetoelectric sensor based on the Hall effect, Characterized by high sensitivity to magnetic fields, stable output signal, high frequency response, strong resistance to electromagnetic interference, simple structure, and ease of use. It mainly consists of permanent magnets with a specific number of pole pairs (generally 4 or 8 pairs), Hall elements, a rotating mechanism, and input/output connectors. Its working principle is that when the sensor's rotating mechanism rotates under external drive, it drives the permanent magnet to rotate, causing the magnetic field passing through the Hall element to change periodically, which causes the output voltage of the Hall element to change, forming a stable pulse voltage signal through subsequent circuit processing, serving as the output signal of the vehicle speed sensor. The main electrical technical parameters of Hall-structure speed sensors include: high-level output voltage, low-level output voltage, duty cycle, period, rise time, fall time, number of pulses per cycle, etc. To ensure product performance reliability, these parameters must be quantitatively tested before leaving the factory. Test systems featuring integration and intelligence, efficient automatic measurement, software calculation, and graphical or tabular display of test results are increasingly favored by vehicle speed sensor manufacturers. A comprehensive testing device developed for performance measurement of commonly used Hall-effect vehicle speed sensors. Based on cost considerations, the high-speed counter port of a microprocessor is used for data acquisition from the vehicle speed sensor, and software control is used to implement calculation and graphical display processing of the acquired data. The completed testing device offers advantages such as high testing precision, reliable data communication, a user-friendly graphical interface, strong anti-interference capability, a simple and intuitive testing process, and low system development cost, and has good market potential for widespread adoption, Therefore, speed sensors have significant application prospects in vehicle speed detection. 2) The speed sensor of the belt conveyor uses a Hall sensor, which is mainly a sensor that utilizes the Hall effect to achieve magneto-electric conversion, The Hall effect has been developing for more than 100 years since it was discovered in 1879, but its application was in the 50s of this century, Due to the rapid development of microelectronics, it has gained attention and widespread adoption, and various types of Hall elements have been continuously developed. China began to increase research on Hall elements in the 70s of the 20th century, After nearly several decades of research and development, it is now possible to produce Hall elements with various performances, such as: ordinary type, high sensitivity type, low temperature coefficient type, temperature and magnetic measurement type, and switch-type Hall elements. Due to the characteristics of Hall sensors such as high sensitivity, good linearity, high stability, small size, and high temperature resistance, they have been widely used in various industrial fields such as non-electrical quantity measurement automatic control, computer devices, and modern military technology.

Weidou Intelligent Technology specializes in selling German SELLA SRL sensors, SELLA SRL proximity sensors, SELLA SRL distance sensors, SELLA SRL vision sensors, SELLA SRL displacement sensors, SELLA SRL load cells, SELLA SRL speed sensors, SELLA SRL photoelectric sensors, SELLA SRL position sensors, SELLA SRL angle sensors, SELLA SRL tactile sensors, SELLA SRL temperature sensors, SELLA SRL pressure sensors, SELLA SRL flow sensors, SELLA SRL level sensors, SELLA SRL motion sensors, SELLA SRL process sensors. Original German imports. Welcome inquiries and orders.