DK-G Series485 Laser Displacement

DK-G belongs to the non-contact laser measurement branch, not the contact-probe family. If the measurement method allows a probe to touch the workpiece, compare contact-type displacement grating sensors instead. These are ordinary measurement devices, not personnel-protective safety sensors.

DK-G is a different family from the DDK-G high-precision series (formerly GDK). Similar housing or a shared catalogue does not make their model codes, ranges or interfaces interchangeable.

The DAIDISIKE DK-G CMOS laser displacement series measures displacement, thickness-related movement, surface profile and vibration within a model-specific window around its nominal standoff. The available center distances are 30, 50, 100, 200 and 400 mm. A reflected spot moves across the receiver as the target moves, and the calibrated sensor converts that position into a measurement.

Select the measurement window, repeatability and output as separate requirements. The confirmed table provides NPN, analog and RS485 order-code rows; analog output is 0–5 V or 4–20 mA, and response is selectable at 1.5, 5 or 10 ms. The IP60 enclosure and −10°C to +40°C operating range require an installation protected from conditions outside those limits. This is an ordinary measurement device, not a safety-rated personnel-protection sensor.

Specifications Table

The table reproduces the confirmed original DK-G ordering and measurement data. A dash marks an unlisted cell, not a claim that a custom version exists or that it is unavailable. DK-G50M is retained exactly as printed; confirm any requested alternative suffix in the quotation instead of substituting one.

Additional Specifications — Confirmed DK-G Factory Table:

• Light source: Red semiconductor laser, 655 nm, maximum output 1 mW; Class 2 as stated in the factory table.
• Supply voltage: 12–24 V DC ±10%; the table specifies 10% P-P ripple.
• Current consumption: Below 40 mA at 24 V DC; below 60 mA at 12 V DC.
• NPN control output: Open-collector output, maximum sink current 50 mA, applied voltage up to 30 V DC; residual voltage below 1.5 V at 50 mA and leakage current below 0.1 mA.
• Output action: Light-ON / Dark-ON selectable.
• Short-circuit protection: Automatic-recovery type, as listed for the control output.
• Analog voltage output: 0–5 V; output impedance 100 Ω. The table identifies +5.2 V as the alarm value.
• Analog current output: 4–20 mA; load impedance 300 Ω or less. The table identifies 0 mA as the alarm value.
• Response time: 1.5 / 5 / 10 ms, switchable. These are response-time settings, not a published sampling-frequency specification.
• External input: NPN non-contact input; active level 0 to +12 V DC; input impedance approximately 10 kΩ.
• Temperature characteristic: 0.03% F.S./°C.
• Protection / pollution degree: IP60; pollution degree 2.
• Operating temperature: −10°C to +40°C; prevent condensation and freezing. Storage: −20°C to +60°C.
• Humidity: 35–85% RH in operation and storage.
• Ambient light: Incandescent illumination at the receiving surface below 3,000 lx.
• Cable: 5-core composite cable, 2 m; conductor cross-section 0.15 mm².
• Housing / weight: Aluminium body with acrylic front cover; approximately 35 g without cable and 85 g with cable.
• Mounting: M3 screws; the outline drawing shows 45.90 × 30.00 × 21.00 mm and φ3.20 mm mounting holes.

Technical Parameters

Unless otherwise specified, the catalogue's measurement conditions are 24 V DC supply, +20°C ambient temperature, 10 ms response, the measurement center distance and a white-paper target. Those conditions matter when comparing repeatability and linearity. For the 400 mm model, the original table divides repeatability into 400 μm at 200–400 mm and 80 μm at 400–600 mm. This counterintuitive interval split is reproduced as printed under the manufacturer's confirmed source; it is not silently changed to the former webpage's 800 μm.

Optical beam diameter is a length: the 100 mm model lists approximately φ200 μm. A pair of dimensions such as 0.15 × 0.15 mm is not a sampling period. The confirmed DK-G table gives selectable 1.5/5/10 ms response times, not a 1 kHz sampling-frequency guarantee or a sub-1 ms measurement cycle. It also does not establish the former 0.1 μm digital resolution, 300 mW consumption, 100 dB dynamic range, 500 G shock endurance or 15-million-cycle cable life claims. Those unrelated or unsupported values are not specifications for this DK-G series.

For PLC integration, match the ordered NPN, analog or RS485 variant and its pinout. The table limits NPN control current to 50 mA; the 100 mA text on an illustrative DK-G200N-RS485 product label is not applied to all models. Analog voltage output impedance is 100 Ω, whereas the 4–20 mA output requires a load of 300 Ω or less. Do not confuse output impedance with a recommended voltage-input load. RS485 identifies the interface row here; confirm the matching protocol and register documentation rather than inferring a universal baud rate or command set.

Working Principle

DK-G uses optical triangulation. A 655 nm red laser illuminates the target, and the receiving optics image the reflected spot onto the CMOS receiver. When the target position changes, the received spot position changes. The sensor's calibrated optical relationship converts that position into a distance or displacement value. Displacement is a difference from a calibrated reference distance: zero displacement means the target is at that reference, not infinitely far away.

The former expression d = (f × b) / Δx was not a valid general displacement formula when Δx was defined as a shift from the reference spot. Do not reconstruct a PLC conversion from that expression; use the selected model's documented analog scale or communication data format.

Target reflectance, texture, angle and ambient light can affect the measurement. The original DK-G instructions specify alignment approximately perpendicular to the target within 90° ±15°, exclude transparent objects and liquids, and explain that the window is not measured from zero. Validate the actual material and geometry for displacement, profile, thickness-related movement or vibration measurement. The mounting instructions also address color/material transitions, rotating targets, steps, recessed surfaces and nearby reflective walls. These are installation considerations, not claims of immunity to color, tilt or reflection.

Author background: Engineer Cai. Content updated September 6, 2026. The company certificate library is background material; request the exact-model declaration and applicable documentation. Published specifications follow the manufacturer-confirmed DK-G table.