I. Model Analysis

7203953: Unique material code for the 3500/40M module

‑01: Standard version (standard temperature, standard firmware, no special customization)

Alias: 3500/40M (market common model)

Position: Pure electric eddy current signal input (only suitable for displacement type probes), different from 3500/42M which can be connected to vibration probes.

II. Core Functions and Applications

Function: Receives signals from 4 eddy current probes (3300XL/7200 series), channel pair configuration (1&2 as one group, 3&4 as another group), capable of monitoring:

Radial vibration (shaft vibration)

Axial displacement (thrust)

Temperature difference (Differential Expansion)

Offset, REBAM (rolling bearing vibration)

Output: Each channel -24 to 0 VDC gap voltage; 4 channels for alarms + 2 channels for dangerous relay contacts; no 4-20mA analog quantity (only 7203954-01 has it).

Application: Critical rotating machinery TSI protection for steam turbines, gas turbines, compressors, etc., focusing on displacement parameter monitoring.

Companion: Compatible with **330104 (8mm), 330106 (11mm), 72072-01 (14mm)** and other probes.

III. Key Technical Parameters

Channels: 4 channels (pair configuration)

Input: Eddy current probes, -10 to +10 VDC

Sensitivity: 7.87 mV/μm (200 mV/mil, compatible with 14mm probes)

Linear range: 2.54 mm (100 mil) per channel

Accuracy: ±0.2% FS

Power consumption: 5.5W (‑24VDC power supply)

Operating temperature: -40℃ to +85℃

Structure: Full-height card, 3500/05 rack installation, supports hot swapping

Configuration: 3500 rack software programming, independent channel alarms.

IV. Core Differences from 3500/42M (7203954-01) Table

Comparison item 7203953-01 (3500/40M) 7203954-01 (3500/42M)

Input type Only eddy current probe (displacement) Eddy current + velocity/acceleration probe (vibration + displacement)

4-20mA output ❌ None ✅ Standard for each channel

Monitoring function Displacement, shaft misalignment, eccentricity vibration, displacement, shaft misalignment, eccentricity, acceleration, velocity

Price Lower Higher

Application scenarios Pure displacement monitoring (for retrofit of old units) Full parameter monitoring of vibration + displacement (for new projects)

V. Replacement and Compatibility

Direct replacement: 3500/40M (7203953-01), available in new or used condition.

Downward compatibility: Can replace 7200 series 72052-01, 72059-01R, etc. Requires reconfiguration.

Upgrade recommendation: When monitoring vibration + displacement simultaneously, prefer 3500/42M (7203954-01).