Overview

The 991 Thrust Transmitter is designed primarily for original equipment manufacturers (OEMs) of centrifugal air compressors, small pumps, motors, or fans. It provides a simple 4 to 20 mA proportional axial displacement (thrust) signal as input to machinery control systems. The transmitter is a 2-wire, loop-powered device that accepts input from the 3300 NSv proximity probe and its matching extension cable (available in 5 m and 7 m system length options). The transmitter conditions the signal into appropriate engineering units proportional to the shaft’s axial position and outputs it as a 4 to 20 mA signal for input to the control system, where machinery protection alarming and logic occur.

Specifications

• Electrical:

  • Input:
    • Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable.
  • Power:
    • Requires +12 to +35 Vdc input at the transmitter terminal.
  • Signal Output:
    • 4 to 20 mAdc over specified full-scale range in 2-wire configuration.
  • Accuracy:
    • Within ±1.5% over specified full-scale range (typical).
    • Accuracy is rated from the TEST signal input to the voltage measured across a 250 Ω loop resistance.
  • Maximum Loop Resistance:
    • 1,000 Ω including cable at 35 Vdc.
  • Current Limiting:
    • 23 mA typical.
  • Zero and Span Adjustments:
    • Non-interacting external adjustments.
  • Not OK/Signal Defeat:
    • Signal output goes to less than 3.6 mA within 100 µs after a Not OK condition occurs.
    • Signal output is restored within 0.1 seconds after the Not OK condition is removed.

• Proximitor Sensor Output:

  • Compatible with ungrounded, portable test equipment.
  • When using grounded, ac-powered test equipment, use the 122115-01 Test Adapter for signal isolation.

• Output Impedance:

  • Prox Out has a 10 kΩ output impedance calibrated for a 10 MΩ load.

• Linear Range:

  • 0.25 to 1.65 mm (10 to 65 mils) for Prox Out.
  • Suitable for 0.6-0-0.6 mm or 25-0-25 mils current loop linear ranges.

• Prox Out Incremental Scale Factor:

  • 7.87 mV/µm (200 mV/mil) ±6.5% typical, including interchangeability errors, when measured in increments of 0.25 mm (10 mils) over the linear range using a flat 30 mm (1.2 inch) target.

• Temperature Stability:

  • Incremental scale factor remains within ±10% of 7.87 mV/µm (200 mV/mil) from 0°C to +70°C (+32°F to +158°F).

• Minimum Target Size:

  • 9.5 mm (0.375 in) diameter.

• Leadwire Length:

  • Proximitor Sensor Output (BNC connector) has a maximum cable distance of 3 meters (10 feet).
  • For non-hazardous, Zone 2 or Div 2 hazardous area locations, up to 13 km (8 miles) maximum between the transmitter and receiving device for signal output.

• Operating Temperature:

  • -35°C to +85°C (-31°F to +185°F).

• Storage Temperature:

  • -51°C to +100°C (-60°F to +212°F).

• Transducer Tip Material:

  • Polyphenylene sulfide (PPS).

• Transducer Case Material:

  • AISI 303 or 304 Stainless Steel (SST).

• Transmitter Weight:

  • 0.43 kg (0.9 lbm).

• Total System Weight:

  • 0.82 kg (1.8 lbm) typical.