Product Overview
The 990-05-70-01-01 is a precision two-wire vibration transmitter from the Bently Nevada 990 Series, designed for continuous, real-time monitoring of rotating machinery. Engineered as a compact, loop-powered device, the 990-05-70-01-01 converts the high-frequency signal from a non-contacting 3300 NSv eddy-current proximity probe into a standard 4–20 mA output proportional to shaft vibration amplitude. This allows machinery health data to be fed directly into a PLC, DCS, SCADA system, or any standard analog input card—without the need for a separate monitoring rack or additional signal conditioning hardware.
The 990-05-70-01-01 is primarily intended for original equipment manufacturers (OEMs) of centrifugal air compressors, as well as operators of small pumps, motors, fans, and blowers, who require a simple, reliable vibration signal for machinery protection and predictive maintenance. Its 0–5 mils peak-to-peak (0–125 μm pp) full-scale range covers the typical vibration envelope of small to medium-sized machines, while the 7.0 m (23 ft) system length accommodates installations where the probe junction is set back from the control panel.
Built to Bently Nevada’s exacting standards, the 990-05-70-01-01 features a fully potted, moisture-resistant enclosure suitable for environments up to 100% condensing humidity. With CSA Division 2 agency approval, DIN rail mounting, and a broad operating temperature range of -35 to +85 °C, it is a rugged, installation-friendly solution for both hazardous and non-hazardous locations.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 990-05-70-01-01 |
| Manufacturer | Bently Nevada (Baker Hughes) |
| Product Type | 2-Wire Vibration Transmitter |
| Series | 990 Vibration Transmitter |
| Measurement Type | Shaft radial vibration (peak-to-peak displacement) |
| Full-Scale Range | 0–5 mils pp (0–125 μm pp) |
| Input | 1 × 3300 NSv non-contacting proximity probe + matching extension cable |
| Output Signal | 4–20 mA DC, proportional to vibration amplitude |
| Configuration | 2-wire, loop-powered |
| Supply Voltage | +12 to +35 VDC at transmitter terminals |
| Loop Accuracy | ±1.5% of specified full-scale range |
| Frequency Response | 5 Hz to 6,000 Hz (+0, -3 dB) |
| Maximum Loop Resistance | 1,000 Ω (including cable, at 35 VDC) |
| Current Limiting | Approx. 23 mA typical |
| Probe Gap Range | 0.5–1.75 mm (20–55 mils) |
| Linear Measurement Range | Approx. 0.25–1.65 mm (10–65 mils) pp |
| PROX OUT | Buffered dynamic signal output via coaxial connector (BNC), 7.87 mV/μm (200 mV/mil) |
| Probe Tip Material | Polyphenylene Sulfide (PPS) |
| Probe Case Material | AISI 303 or 304 Stainless Steel |
| Probe Cable | 75 Ω coaxial, FEP insulated |
| System Length | 7.0 m (23.0 ft) |
| Mounting | 35 mm DIN rail clips (Option 01) |
| Adjustments | Non-interacting external Zero and Span potentiometers |
| Fault Detection | Not OK / Signal Defeat circuit |
| Enclosure | Fully potted, moisture-resistant |
| Enclosure Rating | IP66 / NEMA 4X |
| Operating Temperature | -35 °C to +85 °C |
| Storage Temperature | -51 °C to +100 °C |
| Minimum Target Size | 9.5 mm (0.375 in) diameter |
| Dimensions (W × H × D) | 99 × 74 × 53 mm (approx.) |
| Weight | 0.43 kg (0.9 lb) |
| Agency Approvals | CSA Division 2 |