Vibration Transmitter | 990-06-70-01-05 | Bently Nevada

Technical Specifications

The 990 Vibration Transmitter is intended primarily for the original equipment manufacturers (OEMs) of centrifugal air compressors or small pumps, motors, or fans who prefer to provide a simple 4 to 20 mA proportional vibration signal as the input to their machinery control system. The transmitter is a two-wire, loop-powered device that accepts input from our 3300 NSv proximity probe and its matching extension cable (available in 5 m and 7 m system length options). 

Feature

Integrated Proximitor Sensor requires no external unit

Non-isolated PROX OUT and COM terminals plus a coaxial connector to provide a dynamic vibration and gap voltage signal output for diagnostics

Non-interacting zero and span potentiometers under the Transmitter label supports loop adjustment

Test Input pin for quick verification of loop signal output, using a function generator as the input

A Not OK/Signal Defeat circuit prevents high outputs or false alarms due to a faulty proximity probe or loose connection

Field Installation and Spare Parts Replacement Recommendations

Strict Consistency of Range and Length: The system length is 7 m (-70). Do not mix probes or cables from 5 m systems, or measurement linearity and accuracy will be affected. The full-scale range is 0–100 µm (-06). Configure the PLC/DCS 4–20 mA input to 0–100 µm, not imperial mils.

Single-Point Grounding: Since the transmitter is non-isolated, follow the single-point grounding principle when wiring or using the PROX OUT diagnostic terminal to avoid ground-loop interference and unstable signals.

Technical FAQ

Q: What is the recommended initial gap voltage for installing the probe on the 990-06-70-01-05 transmitter?

A: The initial static gap voltage measured at the test terminal is typically adjusted between -9.0 Vdc and -10.0 Vdc, corresponding to about 1.0 mm installation gap, ensuring operation in the center of the linear range.

Q: How is the 990-06-70-01-05 transmitter powered, and what is the maximum loop resistance?

A: It is powered by a +12 to +35 Vdc 4–20 mA current loop. At 35 Vdc, the maximum loop resistance can reach 1,000 Ω.

Q: What is the function of the PROX OUT and COM terminals on the 990-06-70-01-05 transmitter?

A: These terminals (including coaxial output) provide unfiltered AC vibration signals and DC gap voltage (typically 7.87 mV/µm) for connection to systems like 3500 or portable data collectors without rewiring.

Q: What happens if the probe fails or disconnects on the 990-06-70-01-05 transmitter?

A: The Not OK protection circuit forces the output current below 3.6 mA within 100 µs when a probe fault, short circuit, or severe linear deviation is detected, preventing false alarms or trips.

Q: Are your products brand new?
A: Yes. We only supply 100% original and brand-new products. All items are sourced through authorized channels and have never been used or refurbished.

Q: Why can customers buy with confidence?
A: Because every product is backed by our 1-Year Warranty Guarantee of Quality, ensuring reliability, customer satisfaction, and long-term support after delivery.

Q: Do you provide international shipping?
A: Yes. We ship products to customers worldwide using reliable international logistics services such as EMS, DHL, UPS, and FedEx.

Trusted by 5,000+ plants worldwide |  Contact for more Bently Nevada spares: sales1@amikon.cn

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