991-25-50-01-01 Thrust Transmitter

Overview

Place of Origin:	USA
Brand Name:	Bently Nevada
Model Number:	991-25-50-01-01
Packaging Details:	Original new Factory Sealed
Delivery Time:	5-7 days
Payment Terms:	T/T
Supply Ability:	In stock

Quick Detail

Description

The 991-25-50-01-01 Thrust Transmitter provides precise axial displacement measurement for centrifugal air compressors, small pumps, motors, and fans, converting the input from a 3300 NSv Proximity Probe into a 4–20 mA signal for automated control systems. With a full-scale range of 25-0-25 mils (0.25 to 1.65 mm for Prox Out) and support for 5.0-meter system lengths, the 991-25-50-01-01 delivers accurate shaft thrust feedback even in compact installations. It operates from -35°C to +85°C (-31°F to +185°F) and stores safely at -51°C to +100°C (-60°F to +212°F). The loop-powered 2-wire design requires +12 to +35 Vdc and supports a maximum loop resistance of 1,000 Ω. Output impedance is 10 kΩ calibrated for a 10 MΩ load, with current limiting at 23 mA. DIN-rail mounting with 35 mm clips or bulkhead screws enables fast installation. Integrated Proximitor Sensor, non-isolated Prox Out, and coaxial diagnostic output allow dynamic vibration and gap voltage monitoring. Power-up inhibit and Not OK/Signal Defeat circuits prevent false alarms, while potted construction protects against high humidity. The 991-25-50-01-01 simplifies OEM automation by providing a reliable, loop-powered axial thrust signal from 3300 NSv probes in industrial control systems.

Applications

Axial Thrust Measurement on Centrifugal Compressors
The 991-25-50-01-01 Thrust Transmitter converts the 3300 NSv Proximity Probe gap displacement (0.25–1.65 mm / 10–65 mils) into a 4–20 mA signal, enabling precise axial thrust monitoring in centrifugal compressors. Its 5.0-meter system length option supports installation where clearance is limited, and the full-scale range of 25-0-25 mils allows detection of both forward and reverse shaft movement.

Pump and Motor Axial Position Feedback
Designed for small pumps and motors, the 991-25-50-01-01 provides continuous real-time feedback for automation controllers. Field wiring options from 16–24 AWG ensure signal integrity, while the 10 kΩ output impedance, calibrated for 10 MΩ loads, allows integration with standard control loops without additional signal conditioning.

Vibration and Gap Diagnostics
The 991-25-50-01-01 supports dynamic vibration measurement and gap voltage output through its coaxial connector. This allows operators to monitor shaft health, detect misalignment, and analyze transient events, making it suitable for automated condition monitoring systems.

Specifications

Competitive Advantage

Loop-Powered 2-Wire Efficiency
Operating from +12 to +35 Vdc and supporting up to 1,000 Ω loop resistance, the 991-25-50-01-01 delivers precise 4–20 mA output while minimizing wiring complexity and power requirements.

Quick Mounting and Environmental Durability
With DIN-rail clips and bulkhead screws, installation of 991-25-50-01-01 is fast even in tight machinery enclosures. Its operating temperature range (-35°C to +85°C) and potted construction support high-humidity conditions and protect against condensation.

Signal Integrity and Error Reduction
The 991-25-50-01-01 integrates Power-up Inhibit and Not OK/Signal Defeat circuits to prevent false alarms caused by faulty probes or loose connections. This, combined with current limiting of 23 mA typical and a maximum Proximitor cable distance of 3 meters, ensures consistent axial position measurement.

OEM-Friendly Integration
The 991-25-50-01-01 accepts a single 3300 NSv Proximity Probe input, supporting full system lengths up to 5.0 meters, and provides both Prox Out for diagnostic monitoring and a 4–20 mA signal for direct integration into automated control systems.