Shinkawa VK-202A2 Driver & VL-202A08L-1A72 Proximity Sensor Probe



Shinkawa VK-202A2 Driver and VL-202A08L-1A72 Proximity Sensor Probe assembly forms a non-contact eddy-current displacement measurement system manufactured by Shinkawa Electric. Designed for critical machinery protection systems, this transducer set delivers real-time measurement of shaft vibration, axial displacement (thrust), phase reference (Keyphasor), and rotational speed on high-speed industrial rotating machinery.

Product Introduction / Overview

By emitting a high-frequency electromagnetic field from the tip of the VL-202A08L-1A72 probe, the system detects minute variations in the gap between the probe tip and the rotating metallic shaft surface. The VK-202A2 driver conditions these eddy-current impedance shifts into a highly accurate, linear negative DC voltage output directly proportional to the physical distance. The system is widely deployed across turbomachinery, boiler feed pumps, gas compressors, and power generation turbines.

Technical Table

Environmental Tolerance Conditions

Operating Temperature (Probe VL): -30°C to +177°C (-22°F to +350°F) high-temperature target area

Operating Temperature (Driver VK): -20°C to +70°C (-4°F to +158°F)

Storage Temperature (Combined System): -30°C to +85°C (-22°F to +185°F)

Relative Humidity: 5% to 95% non-condensing

Probe Pressure Resistance: Tip withstands up to 0.5 MPa (5 bar) differential pressure

Enclosure Protection: Probe IP67 (oil/water tight); Driver IP20 (requires IP54 field terminal housing)

Operating Instructions

Physical Probe Mounting: Thread the VL-202A08L-1A72 probe into the bearing housing bracket. Ensure the probe tip is perpendicular to the shaft surface without tilting.

Gap Voltage Calibration: Connect a digital multimeter to the VK-202A2 driver output terminals (SIG and COM). Adjust physical probe depth until the voltage reads the target electrical zero (typically -9.0 V DC to -10.0 V DC, corresponding to ~1.0 mm mid-range gap).

Locking & Cable Routing: Tighten probe mounting lock nuts. Secure armored cable runs to prevent high-vibration fatigue. Clean coaxial connectors with isopropyl alcohol before mating.

Shield Connection: Connect outer cable shielding to the ground terminal at the main monitor rack only to prevent ground loop currents.

Fault Diagnosis & Troubleshooting

Output Voltage Stuck at -21 V to -24 V DC (Supply Voltage): Indicates an open circuit. Check probe extension cable connectors, inspect for broken coaxial center pins, or check for probe tip rupture.

Output Voltage Stuck near 0 V to -1 V DC: Indicates probe tip is touching the target shaft (zero gap) or a short circuit in the probe coaxial line.

Unstable Signal / High Noise Reading: Inspect cable shielding for missing chassis ground connection; check for strong external magnetic fields or ungrounded machine shafts.

Non-Linear Output / Reduced Sensitivity: Verify target material (non-4140 steel alloys require recalibration); clean oil sludge/metallic debris build-up off the probe tip face.

Related Models in the Same Series

VK-202A Series: Base preamplifier/driver unit family for proximity systems

VL-202A Series: Proximity sensor probe family (various thread configurations and cable lengths)

BH-150 / BH-150-03: Alternative signal conditioner/driver options

VM-3D2: Dual-channel thrust/axial position rack monitor module

VM-3V2: Dual-channel shaft vibration monitor module

Storage Conditions

Environment: Clean, dry indoor storage free from corrosive gases, solvent fumes, and airborne metal dust.

Relative Humidity: Maintain below 95% non-condensing.

Connector Care: Keep protective plastic caps installed on all coaxial connectors until final field installation. Store probe cables coiled with a minimum bend radius of 50 mm.