Description
Product Description
The AI-TEK 70085-8080-004 is a passive magnetic speed sensor. It delivers reliable speed detection for industrial machinery. This sensor works without external power. Its robust design suits harsh environments. Use it for RPM monitoring, speed control, and position sensing.
Key Features & Benefits
- Self-powered operation – No external supply needed
- Wide temperature range -30 to +85°C for versatile use
- High output voltage 55 V (P-P) standard signal
- Long cable option 10 meters for remote mounting
- Simple two-wire connection White lead positive
Technical Specifications
- Brand: AI-TEK
- Model: 70085-8080-004
- Series: 70085 Series
- Output Type: Analog sine wave (passive magnetic)
- Output Voltage (Standard): 55 V (P-P)
- Guaranteed Output Voltage: 4.2 V (P-P) at specified point
- Typical Inductance: 125 mH reference
- DC Resistance: 960 ohms maximum
- Thread Size: .375 inch (no thread)
- Thread Length: 2.5 inches
- Sensor Length: 2.5 inches
- Conduit Thread: 1/2 NPT
- Termination: Cable, lead length 6 inches (15.2 cm)
- Total Cable Length Option: 10 meters (model suffix -004)
- Operating Temperature: -30 to +85°C
- Agency Approval: None
- Net Weight: 3 oz max.
- Output Polarity: White lead positive
Performance Parameters
- Measurement Range: 0 to 20 kHz typical
- Frequency Response: 100 Hz to 15 kHz (signal amplitude varies with speed)
- Sensitivity: 55 V (P-P) at high speed, 4.2 V (P-P) guaranteed low speed
- Linearity: Excellent near zero speed due to passive design
- Resolution: Detects single tooth or slot per revolution
- Environmental Resistance: IP67 equivalent when properly mounted
- Noise Immunity: High due to magnetic pickup principle
Installation Guide
- Mounting: Use 1/2 NPT conduit thread for secure fitting
- Air Gap: Set 0.005 to 0.015 inch from gear tooth
- Target Material: Use ferrous metal gear or wheel
- Orientation: Mount perpendicular to target movement
- Cable Routing: Keep away from high voltage lines
- Torque: Tighten to 15-20 in-lbs maximum
Calibration & Maintenance
- Calibration not required – Factory set passive device
- Maintenance free – No moving parts inside
- Clean sensor tip occasionally with soft cloth
- Check cable for cuts or abrasion yearly
- Verify air gap after mechanical repairs
- No software or firmware updates needed
Compatibility
- Works with all PLC digital input modules (5-24V DC)
- Compatible with frequency counters and tachometers
- Connects to AI-TEK signal conditioners (model 70085-8080 series)
- Replaces obsolete Honeywell or Airpax speed sensors
- Output matches standard magnetic pickup inputs
Diagnostic Capability
- Measure DC resistance (960 ohms max) to check coil health
- Spin target manually – observe AC voltage on multimeter
- No output? Check air gap and target ferrous metal
- Low output? Clean tip or reduce gap distance
- Use oscilloscope to see sine wave amplitude versus speed
Typical Applications
- Motor speed feedback for VFD drives
- Conveyor belt RPM monitoring
- Pump and fan overspeed protection
- Diesel engine timing reference
- Gearbox shaft speed measurement
- Turbine rotational speed detection
Package List
- 1x AI-TEK 70085-8080-004 speed sensor
- Built-in 6 inch (15.2 cm) pigtail cable
- Installation sheet (digital download available)
Warranty & Shipping
- 12-month warranty against manufacturing defects
- Free replacement for DOA or failure within 12 months
- Express shipping via FedEx, UPS, or DHL – Worldwide tracking
- Typical delivery: 3-7 business days
Frequently Asked Questions (FAQ)
- Does this sensor need power?
No. It is a passive magnetic pickup. The target motion generates voltage. - What is the minimum speed for 4.2V output?
Depends on gear size. Typically 100 to 300 RPM with a 8-pitch gear. - Can I cut the cable shorter?
Yes, but keep at least 3 feet for signal strength. Re-seal the end. - Why does my reading show zero at low speed?
Air gap too large. Reduce gap or use a higher tooth count gear. - Is this sensor waterproof?
It resists splashing and humidity. Not for submersion. - Experience: I get noise on the signal.
Use shielded twisted pair cable. Connect shield to ground at PLC end. - Experience: Output voltage drops after one year.
Check magnet strength. Rare failure – replace sensor if weak. - Buying guide: Which cable length should I choose?
Model -004 has 10m cable. For shorter runs, pick -314 (3.05m). - Buying guide: Can this sense non-ferrous targets?
No. Only ferrous metals like steel or iron work. - Buying guide: Difference between 70085 and 70084 series?
70085 has longer 2.5 inch thread for thicker mounting walls.
Selection Guide
- Step 1 – Target material: Must be ferrous metal (steel, iron)
- Step 2 – Speed range: 70085 works from near-zero to 20,000 RPM
- Step 3 – Mounting thread: .375 inch smooth bore (use clamp or epoxy)
- Step 4 – Temperature: -30 to +85°C covers most industrial sites
- Step 5 – Cable length: -004 = 10m, -314 = 3.05m
- Expert tip: Use signal conditioner 70085-8080-001 for long cable runs (>30m)
Contact & Support
For technical help or bulk orders: +86 158 8020 0923 (WhatsApp)
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