991-01-XX-01-00 MOD 288865-01 belongs to the Bently Nevada 991 family of two-wire axial-position transmitters. It accepts a matching 3300 NSv proximity chain and sends a proportional thrust-position signal to a machinery control system.

Both the 01 full-scale field and XX system-length field fall outside the current standard public ordering combinations. Exact calibration limits and total chain length must therefore be verified from the MOD documentation.

• Converts shaft axial position into a control-system current signal.
• Offers test input, independent zero/span controls and buffered diagnostic access.
• Suppresses false high output when the probe circuit is invalid.
• Uses potted construction for high-humidity industrial environments.

• Confirm the MOD-specific range and total probe-system length before supply.
• Match the probe thread, target material, extension cable and connector arrangement.
• Verify that the controller provides the required thrust alarming and logic functions.
• Do not treat a PLC loop as equivalent to a full machinery-monitoring platform with advanced bypass and diagnostic functions.

• Record normal and counter-direction calibration points before removing the transmitter.
• Preserve the exact sensor chain because axial-position range depends critically on probe adjustment.
• Restore zero, span and controller limits using the approved commissioning procedure.
• Prove direction, full travel, not-OK handling and final trip logic under controlled conditions.