990-10-70-01-CN Bently Nevada 990 Vibration Transmitter

Product Overview

The Bently Nevada 990-10-70-01-CN is a high-performance 2-wire vibration transmitter designed to provide a 4 to 20 mA output proportional to radial vibration. It is specifically engineered to interface with 3300 NSv proximity probes and extension cables, making it ideal for monitoring small-diameter shafts or machines with restricted mounting spaces.

Proudly Made in the U.S.A., this transmitter integrates the functions of a Proximitor sensor and a signal conditioner into a single, compact unit. It is perfect for direct PLC/DCS integration in industrial machinery protection systems.

Technical Configuration

• Model: 990 Vibration Transmitter
• Full-scale Option (-10): 0-10 mils pp (0-250 μm pp)
• System Length (-70): 7.0 meters (23.0 feet)
• Mounting Option (-01): 35 mm DIN rail clips
• Agency Approval (-CN): Country Specific Approvals

Technical Specifications

Installation & Calibration

The 990 transmitter is designed for easy 35 mm DIN rail mounting. For accurate measurement, the probe must be gapped between 0.5 and 1.75 mm (20 and 55 mils) from the target. The unit features non-interacting external zero and span adjustments for fine-tuning in the field.

Advanced Features

NOT OK / Signal Defeat: In the event of a probe failure or "Not OK" condition, the signal output drops below 3.6 mA within 100 µs to prevent false vibration readings. This ensures high system integrity and prevents unwarranted machine trips.

Technical FAQs

Q1: What probe is compatible with the 990 transmitter?

A1: It is exclusively designed to work with the Bently Nevada 3300 NSv non-contacting proximity probe and its matching extension cable.

Q2: Why is the system length important?

A2: This model (-70) is calibrated for a 7.0-meter total electrical length. The combined length of your probe and extension cable must match this exactly for accurate readings.

Q3: Does this require a separate Proximitor?

A3: No. The 990 Transmitter combines the Proximitor functions and outputs a 4-20mA signal directly, simplifying your wiring architecture.

Shipping Weight: 0.6 kg (estimated with packaging)