991 Thrust Transmitter | Bently Nevada | 991-01-XX-01-00

Electrical Specifications

Input:

• Accepts one non-contacting 3300 NSv Proximity Probe and extension cable.

Power Requirements:

• Voltage: +12 to +35 Vdc at the transmitter terminal.

Signal Output:

• Current: 4 to 20 mA over the specified full-scale range in a 2-wire configuration.

Accuracy:

• Within ±1.5% over the specified full-scale range (typical). Accuracy is based on 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.

Adjustments:

• Non-interacting external zero and span adjustments.

Not OK/Signal Defeat:

• Signal output will drop 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 condition is resolved.

Proximitor Sensor Output:

• Compatible with ungrounded, portable test equipment. Use the 122115-01 Test Adapter for signal isolation when using grounded, ac-powered test equipment.
• Output impedance: Prox Out has a 10 kΩ output impedance calibrated for a 10 MΩ load.

Performance Specifications

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.

Incremental Scale Factor:

• 7.87 mV/µm (200 mV/mil) ±6.5% typical, including interchangeability errors 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), maximum cable distance is 3 meters (10 feet).

Hazardous Area Locations:

• 13 km (8 miles) maximum between transmitter and receiving device for signal output.

Environmental Limits

Transmitter Temperature:

• Operating: -35°C to +85°C (-31°F to +185°F).
• Storage: -51°C to +100°C (-60°F to +212°F).

Probe Temperature:

• Operating: -52°C to +177°C (-62°F to +351°F).
• Storage: -52°C to +177°C (-62°F to +351°F).

Humidity:

• 100% condensing, non-submerged, with protection of coaxial connectors.

Mechanical Specifications

Transducer Tip Material:

• Polyphenylene sulfide (PPS).

Transducer Case Material:

• AISI 303 or 304 Stainless Steel (SST).

Probe Cable:

• 75Ω coaxial, fluoroethylene propylene (FEP) insulated.

Cable Armor (optional):

• Flexible AISI 302 SST with optional FEP outer jacket.

Tensile Strength:

• 222 N (50 lbf) from probe case to probe lead, maximum.

Transmitter Weight:

• 0.43 kg (0.9 lbm).

Total System Weight:

• 0.82 kg (1.8 lbm) typical.