CA280 144-280-000-115 Meggitt Piezoelectric Accelerometer

CA280 144-280-000-115 is a high-sensitivity piezoelectric accelerometer with integral cable from the Meggitt Vibro-Meter product line. This model belongs to the integral cable version introduced in the early stages of the CA280 series (approximately 2015 and earlier). It comes standard with a 3-meter low-noise, shielded twisted pair cable (K205 type), with the cable protected externally by a flexible stainless steel braided hose that is hermetically welded to the sensor body, forming a completely sealed integral assembly. This design eliminates the need for on-site cable connection after installation, greatly simplifying field wiring work while ensuring long-term reliability, making it particularly suitable for industrial environments with limited space, difficult wiring, or strict sealing requirements.

The 144-280-000-115 inherits the core technology of the CA280 series—symmetrical shear mode piezoelectric sensing element, internal case insulation, and differential output—effectively suppressing ground loop interference and ensuring signal quality. Its fully welded AISI 316L stainless steel case provides excellent corrosion resistance and mechanical strength, enabling stable operation within the extreme temperature range of -60°C to +260°C. It has obtained multiple international explosion-proof certifications including ATEX, IECEx, and cCSAus, permitting safe use in potentially explosive gas atmospheres such as Zone 0, 1, and 2.

As an early integral cable version of the CA280 series, the 144-280-000-115 has been widely applied in critical equipment such as gas turbines, compressors, and aero-engine testing, serving as a reliable spare part choice for existing system maintenance and specific functional requirements.

II. Key Features and Benefits

1. Excellent Measurement Performance

• High Sensitivity (100 pC/g) : Capable of accurately capturing vibrations as low as 0.01 g, suitable for precision machinery and structural analysis.

• Wide Frequency Response (0.5 Hz to 6000 Hz) : Covers the vibration frequencies of most rotating machinery while allowing accurate measurement of both low and high-frequency components.

• Low Transverse Sensitivity (≤3%) : Ensures measurement primarily along the sensitive axis, reducing interference from transverse vibrations.

• Low Base Strain Sensitivity (typical 0.8×10⁻³ g/με) : Effectively isolates the influence of mounting surface strain on measurement results.

2. Rugged Integrated Construction

• Fully Welded AISI 316L Stainless Steel Case: Provides excellent corrosion resistance and mechanical strength with high protection level.

• Integrally Welded Cable Assembly: The cable is welded to the sensor via a stainless steel braided hose, preventing ingress of moisture and corrosive gases, suitable for harsh industrial environments.

• Internal Case Insulation: The sensor is electrically floating relative to the case, avoiding ground loops and improving signal integrity.

• Wide Operating Temperature Range (-60°C to +260°C): Can withstand extreme temperatures, suitable for high-temperature turbomachinery and low-temperature environments.

• Shock Resistance (<1000 g): Able to withstand accidental mechanical shocks, ensuring sensor survival in harsh operating conditions.

3. International Explosion-Proof Certifications

• Multiple Certifications including ATEX, IECEx, cCSAus, EAC: Suitable for potentially explosive atmospheres, including Zone 0, 1, and 2 gas environments.

• Intrinsic Safety Ex ia and Non-Sparking Ex nA: Different protection modes available based on application requirements, ensuring safe operation.

4. Convenient Installation and Connection

• ARINC 554 Standard Mounting: Fixed using three M4 screws with a mounting torque of 4 N·m, no need for electrical insulation of the mounting surface.

• Pre-installed Integral Cable: Factory-welded 3-meter K205 low-noise cable with flying leads at the end, facilitating direct connection to signal conditioners or monitoring systems.

• No On-site Wiring Required: Reduces the risk of installation errors and improves system reliability.

5. No Subsequent Calibration Required

• Factory Dynamic Calibration: Each sensor is calibrated at 120 Hz, 5 g peak, 23°C, with a sensitivity tolerance of ±5%. No periodic calibration is necessary.

  
  

III. Typical Applications

Leveraging its integrated cable design, high sensitivity, wide temperature range, and explosion-proof characteristics, the CA280 144-280-000-115 is primarily used in the following scenarios:

• Rotating Machinery Vibration Monitoring: Such as gas turbines, steam turbines, compressors, fans, pumps, for condition monitoring and fault diagnosis, particularly suitable for locations with limited installation space and difficult wiring.

• Aerospace Testing: Engine vibration testing, structural modal analysis, flight vehicle health monitoring, requiring high reliability and high-temperature resistance.

• Petrochemical Industry: Online vibration monitoring in hazardous areas, such as critical equipment in refineries and chemical plants. The integral cable design reduces explosion-proof interfaces, enhancing safety.

• Power and Energy: Vibration measurement for generator sets, wind turbines, auxiliary equipment in nuclear power plants.

• Laboratory Research: Material mechanical testing, structural dynamics research, high-precision vibration measurement; the integral cable ensures signal stability.

• Extreme Environment Monitoring: Long-term vibration monitoring under high/low temperature, high humidity, and corrosive atmospheres.

  
  

IV. Operating Principle and System Integration

1. Operating Principle

The CA280 operates on the piezoelectric shear mode principle: an internal seismic mass applies a shear force to the piezoelectric element under acceleration, generating a charge signal proportional to the acceleration. Due to the differential output and internal insulation, this charge signal manifests as a potential difference between the two pins, effectively suppressing common-mode interference. In the integral cable version, the K205 low-noise cable transmits the differential charge signal from the sensor to the external signal conditioner, and the cable's shielding further suppresses electromagnetic interference.

2. Signal Conditioning Requirements

As the CA280 outputs a high-impedance charge signal, it must be connected to an external charge converter (such as Meggitt's IPC70x series signal conditioners) or a monitoring system with a charge input. The charge converter transforms the charge signal into a low-impedance voltage signal and may provide functions like integration and filtering, facilitating subsequent data acquisition and analysis. For the integral cable version, the cable capacitance is already included in the total load; when selecting a charge converter, its compatibility with the cable length should be considered.

3. System Integration Key Points

• Cable Fixation: Although the stainless steel braided hose of the integral cable is robust, it still requires proper fixation to avoid fatigue damage from vibration. It is recommended to secure the cable using a clamp approximately 100 mm from the sensor.

• Grounding and Insulation: The sensor case is electrically connected to the mounting surface, but the internal circuit is insulated from the case. Therefore, no special insulation treatment is required for the mounting surface. System grounding should follow the single-point ground principle to avoid ground loops. The cable shield should be grounded at a single point, preferably at the charge converter end.

• Installation in Hazardous Areas: When used in hazardous areas, special conditions from the Ex certificates must be followed, such as limitations on cable capacitance and inductance, and anti-static measures during installation. The length and capacitance parameters of the integral cable are already included within the Ex certification scope, requiring no additional calculation.

• Interfacing with Monitoring Systems: Connect the voltage signal from the charge converter to VM600 monitoring systems, data acquisition cards, or PLC analog input modules. Configure range, alarm thresholds, etc., via configuration software.

  
  

V. Version Positioning and Selection Recommendations

1. Positioning within the CA280 Series

The 144-280-000-115 is an early integral cable version (3-meter cable length) within the CA280 series. Compared to the later-released 144-280-000-116 (also a 3-meter integral cable version), the main differences might include:

• Part Number Update: 116 likely supersedes 115, but performance specifications are essentially identical.

• Hardware Tweaks: 116 may incorporate updated manufacturing processes or components, not detailed in public documents.

• Certification Continuity: The 116 version maintains the same level of explosion-proof certifications.

2. Comparison with Other Versions

3. Selection Decision Recommendations

• Existing System Spare Parts: If the existing system uses the 115 version, it is recommended to continue procuring 115 or confirm that 116 is directly replaceable (verify mounting dimensions and electrical interface are identical). Since 115 is an early part number, it may have been superseded by 116; consult with Meggitt to confirm compatibility during procurement.

• New Project Selection: For new projects, it is recommended to prioritize currently available integral cable versions (such as 116 or 126), as these versions feature the latest manufacturing processes and ongoing technical support. If the project requires special cable lengths (other than 3m or 6m), the sensor-only version with user-supplied cable should be selected.

• Special Temperature Requirements: If the application temperature exceeds the rating of the K205 cable (-60°C to +260°C), the sensor-only version must be used with special cables having a higher temperature rating.

• Explosion-proof Compliance: Regardless of the version chosen, verify that its explosion-proof marking meets the requirements of the site's hazardous area classification (e.g., Zone 0, 1, 2). The integral cable version, with the cable pre-installed, has the explosion-proof certification covering the entire assembly, making it simpler to use.

4. Compatibility Notes with Newer Models

The CA280 series may later introduce hardware revision versions (e.g., different suffixes), but basic performance remains consistent. When replacing or mixing, it is recommended to:

• Check if mounting dimensions are identical (especially the ARINC 554 fixing holes).

• Confirm the cable exit direction is the same (radial or axial) to avoid installation interference.

• Verify if explosion-proof certifications cover the required area.