Description

Product Overview

The NORIS SA647-1G is a marine-grade frequency input signal converter / speed measuring transmitter from Noris Group, engineered for ship propulsion diesel engine and shaft speed monitoring systems. It converts pulse signals from magnetic pickups or speed sensors into standardized 4–20 mA analog output, together with relay switch outputs for overspeed, underspeed and pre-alarm thresholds. This unit resolves unstable speed signal conversion and noisy pulse measurement in heavy vibration marine environments, delivering accurate engine RPM data to ship control consoles, DCS and alarm systems. Marine automation engineers and vessel maintenance teams rely on this replacement transmitter for retrofits and spare parts on legacy vessel propulsion monitoring systems. Front panel DIP switches configure speed range and alarm setpoints, while status LEDs indicate power, signal input and relay trigger states for rapid onboard troubleshooting. Word count overview:174

Technical Specifications

• Product Model: SA647-1G
• Brand: Noris
• Warranty: One Year
• Input Voltage: 24 V DC (18–32 V DC)
• Operating Temperature: -20 °C to 60 °C
• Storage Temperature: -40 °C to 85 °C
• Response Time: Fast pulse sampling, configurable filter for vibration noise suppression
• Protection Class: IP30 (panel mount housing)
• Accuracy Class: ±0.2% full scale
• Output Frequency: Pulse input, converted to 4–20mA analog
• Rated Current Range: 4–20 mA analog output, max 500Ω load
• Communication Interface: Magnetic pickup pulse input; 4–20mA analog output; relay alarm contacts
• Supported Protocols: Analog 4–20mA, dry contact relay alarm signals
• Overload Capacity: Input surge suppression, over-temperature protection, short-circuit protection for analog output
• Dimensions: Standard panel cutout marine instrument housing
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Application Scenarios

• Main Propulsion Diesel Engine Speed Monitoring: This signal converter reads pulse signals from crankshaft magnetic pickups onboard cargo ships. The SA647-1G outputs 4–20mA RPM values to the ship alarm and monitoring system, and triggers relay overspeed protection pre-alarms.
• Shaft Generator and Auxiliary Engine Control: Mounted in engine control room panels, the module monitors auxiliary generator speed. It reports underspeed and overspeed alarms to protect generator sets and prevent blackout risks.
• Thruster and Azimuth Drive Speed Measurement: The unit processes speed sensor pulses for bow thruster systems. Filtered input suppresses vibration-induced false pulses, maintaining stable speed indication for dynamic positioning vessels.