DK-G Series485 Laser Displacement

The DAIDISIKE DK-G series CMOS laser displacement sensor is a high-precision, non-contact optical measurement device designed for precision industrial applications, such as displacement detection, thickness measurement, surface profile scanning, and vibration analysis. This series employs advanced CMOS image sensor technology combined with the laser triangulation principle to achieve micron-level accuracy measurements, supporting various models to adapt to different measurement ranges, including short-range (30mm to 50mm), mid-range (100mm to 200mm), and long-range (400mm). The sensor detects changes in the position of reflected light on the CMOS by emitting a red visible laser (wavelength approximately 665nm, power less than 1mW) to calculate the displacement or distance of the target object. Product features include high repeatability (minimum 10μm), low linearity error (starting from ±0.1% F.S.), small spot size (starting from φ50μm), and strong anti-interference capabilities, supporting NPN/PNP switching outputs and analog outputs (voltage/current). The DAIDISIKE brand focuses on compact design and durability, with an aluminum alloy housing and IP64 (sensor head) / IP67 (cable connection) protection rating, suitable for harsh environments such as automotive parts inspection, electronics manufacturing, semiconductor processing, and material winding control. This series of sensors complies with IEC/JIS/FDA laser safety standards (Class 2/Class II), with electromagnetic compatibility (EMC) certified by CE, and is easy to integrate into PLC or industrial control systems. Advanced features include multi-mode detection (diffuse reflection/specular reflection), adaptive light intensity adjustment, and external trigger input, supporting high-speed sampling rates (up to 1kHz) for real-time dynamic measurements.

Specifications Table

The following is a detailed specifications table for the DK-G series sensors, categorized by measurement center distance, including short-range, mid-range, and long-range types. The table covers models, measurement ranges, accuracy indicators, light source parameters, power requirements, output modes, environmental adaptability, and other key specifications. Some models support analog output (M suffix).

Additional Specification Details (Applicable to All Models Unless Specified Otherwise):

• Light Source: Red semiconductor laser, wavelength 665nm, maximum output power 1mW (Class 2 laser product, compliant with IEC/JIS/FDA standards).
• Resolution: 0.1μm (short-range) to 10μm (long-range), sampling period 0.15x0.15mm (near end) to 1.75x3.5mm (far end).
• Power Supply Voltage: 12-24V DC ±10%, ripple (P-P) ≤5%.
• Current Consumption: Maximum 60mA (switching output type), 50mA (analog output type).
• Switching Output: NPN/PNP open collector, maximum load 100mA/DC30V, residual voltage 1.8V or less.
• Analog Output: Voltage -5V to +5V (load resistance 100Ω), current 4-20mA (load resistance 300Ω or less); linear output range corresponds to measurement range, temperature drift ±0.08% F.S./°C.
• Response Time: Fast mode max. 2ms, standard mode max. 11.5ms, high-precision mode max. 48.5ms, switchable via external input.
• External Input (MF Input): NPN/PNP, multi-function input for mode switching, laser off, or zero reset, input resistance 10kΩ.
• Protection Rating: IP64 (sensor head), IP67 (cable connection).
• Operating Temperature: -10°C to +45°C (no condensation), storage temperature -20°C to +60°C.
• Operating Humidity: 35% to 85% RH (no condensation), storage humidity 35% to 95% RH.
• Vibration Endurance: 10 to 55Hz, double amplitude 1.5mm, 2 hours in each X/Y/Z direction.
• Shock Endurance: Approx. 500G, 3 times in each X/Y/Z direction.
• Weight: Sensor head approx. 90g (excluding cable), cable approx. 50g/m.
• Material: Aluminum alloy housing, polymethyl methacrylate (PMMA) lens, PVC cable sheath (φ5-6mm, 6-8 cores, AWG24).
• Cable Length: Standard 2m, bending life over 15 million cycles.
• Mounting Method: M3 screw fixation, detection modes support diffuse reflection/specular reflection/transmissive.
• EMC Compliance: Compliant with EN standards, strong noise resistance.

Technical Parameters

The technical parameters of the DAIDISIKE DK-G series emphasize high resolution and stability, supporting multi-point calibration and real-time data processing. The sensor resolution is as low as 0.1μm, with a sampling rate up to 1kHz, linearity accuracy ±0.1% F.S. (Full Scale), repeatability ±0.05% F.S., and temperature drift coefficient ≤0.08%/°C. It integrates a digital signal processor (DSP) and analog-to-digital converter (ADC) to compensate for ambient light interference, surface reflectance variations, and tilt angle errors (maximum ±15°). Laser power control uses an automatic power control (APC) mechanism to ensure output stability. Data output supports ASCII/binary formats. Power consumption is as low as 300mW, suitable for portable devices. Advanced parameters include adjustable spot size (via focal length adjustment), dynamic range (DR) exceeding 100dB, electromagnetic interference (EMI) resistance compliant with industrial standards, and built-in filters (such as median filtering, moving average) to reduce noise. Compared to traditional inductive or ultrasonic sensors, this series provides higher accuracy and speed in non-contact measurements, ideal for micron-level applications like semiconductor wafer thickness inspection or precision mechanical assembly.

Working Principle

The working principle of the DAIDISIKE DK-G series CMOS laser displacement sensor is based on laser triangulation technique, an optical non-contact measurement method widely used in precision engineering. The sensor contains a semiconductor laser diode (Semiconductor Laser Diode) that emits a red visible laser beam (wavelength approximately 665nm), focused through a collimating lens (Collimating Lens) into a small spot beam projected onto the target object surface. The laser undergoes diffuse reflection (Diffuse Reflection) or specular reflection (Specular Reflection) on the surface, and the reflected light is imaged via a receiving lens (Receiving Lens) onto a linear CMOS image sensor (Linear CMOS Image Sensor), which consists of a high-resolution pixel array (Pixel Array) that precisely detects the center position of the spot (Centroid Position).

According to the triangulation principle, the sensor calculates the geometric relationship of the triangle formed by the emitted beam, reflected beam, and object surface. The specific formula is: displacement distance d = (f * b) / (Δx), where f is the focal length of the receiving lens (Focal Length), b is the baseline distance between the transmitter and receiver (Baseline Distance), and Δx is the position shift of the spot on the CMOS (from reference position x0 to actual position x'). Through the built-in analog-to-digital converter (Analog-to-Digital Converter, ADC) and microcontroller unit (Microcontroller Unit, MCU), it processes pixel data in real-time to convert it into digital displacement values. This process involves signal amplification (Signal Amplification), noise filtering (Noise Filtering), and linearization correction (Linearization Correction), unaffected by target color, texture, or slight tilt (under compensation algorithms). The sensor also integrates a photodiode (Photodiode) for laser intensity monitoring, enabling automatic power control (Automatic Power Control, APC) to maintain light source stability. The entire measurement cycle is less than 1ms, supporting high-speed dynamic measurements, such as vibration analysis (Vibration Analysis) or in-line quality control (In-Line Inspection). Compared to capacitive (Capacitive) or eddy current (Eddy Current) sensors, the laser triangulation method offers a longer measurement range (up to ±200mm) and higher accuracy, but attention should be paid to surface roughness (Ra < 10μm) and ambient light interference to avoid measurement errors.

Specs reviewed by Engineer Cai, Senior Application Engineer. CE-certified & Class 2 laser compliant — see certificates.