CA280 144-280-000-015 Meggitt Piezoelectric Accelerometer

CA280 144-280-000-015 is a high-sensitivity piezoelectric accelerometer from the Meggitt Vibro-Meter product line, specifically designed for low-amplitude vibration measurement and analytical applications. This model designates the sensor-only version (without integral cable) , featuring a symmetrical shear mode measuring element with internal case insulation and differential output, effectively suppressing ground loop interference and ensuring signal quality. Its rugged, hermetically welded AISI 316L stainless steel case enables it to withstand extreme industrial environments and potentially explosive atmospheres, making it an ideal choice for vibration monitoring in aerospace, energy, chemical, and other industries.

As the base version of the CA280 series, the 144-280-000-015 does not include an integral cable, allowing users to flexibly select appropriate cables based on the specific temperature requirements and installation conditions of the application. This version is equipped with a high-temperature circular 2-pin connector (7/16"-27UNS-2A) and is compatible with various low-noise cable assemblies. The sensor itself has obtained international explosion-proof certifications and can operate safely in hazardous areas such as Zone 0, 1, and 2.

This product represents a typical configuration of the CA280 series during its early promotion phase (approximately 2015 and earlier). Its stable performance and clear explosion-proof certifications have enabled its widespread application in numerous industrial sites. For the maintenance of existing systems and applications with well-defined functional requirements, this model remains a reliable spare part choice.

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 values of 0.2×10⁻³ g/με (older document) or 0.8×10⁻³ g/με (newer document), effectively isolating the influence of mounting surface strain on measurement results.

2. Rugged Mechanical Design

• Fully Welded AISI 316L Stainless Steel Case: Provides excellent corrosion resistance and mechanical strength, with a high protection level suitable for harsh environments such as humidity and corrosive gases.

• 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. Flexible Mounting 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.

• Detachable Cable Design: The sensor-only version (015) allows users to select cables of appropriate length and temperature rating based on site conditions, reducing spare parts inventory.

• High-Temperature Connector: 7/16"-27UNS-2A threaded interface, mates with CG505 or similar connectors, ensuring reliable electrical connection.

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 high sensitivity, wide temperature range, and explosion-proof characteristics, the CA280 144-280-000-015 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.

• Aerospace Testing: Engine vibration testing, structural modal analysis, aircraft health monitoring.

• Petrochemical Industry: Online vibration monitoring in hazardous areas, such as critical equipment in refineries and chemical plants.

• 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.

• 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.

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.

3. System Integration Key Points

• Cable Selection: For the 144-280-000-015 version, choose low-noise, shielded cables with an appropriate temperature rating. Meggitt recommends the K205 type twisted shielded cable (suitable for -60°C to +260°C), ensuring the connector matches 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.

• 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.

• 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 144-280-000-015 is an early sensor-only version within the CA280 series. Compared to the later-released 144-280-000-016 (also a sensor-only version), the main differences might include:

• Part Number Update: 016 likely supersedes 015, but performance specifications are essentially identical.

• Hardware Tweaks: 016 may incorporate updated manufacturing processes or components, not detailed in public documents.

• Certification Continuity: The 016 version maintains the same level of explosion-proof certifications.

2. Comparison with Other Versions (with Integral Cable)

3. Selection Decision Recommendations

• Existing System Spare Parts: If the existing system uses the 015 version, it is recommended to continue procuring 015 or confirm that 016 is directly replaceable (verify mounting dimensions and electrical interface are identical).

• New Project Selection: For new projects, it is recommended to prioritize versions with integral cable (116 or 126), as the integral cable is pre-installed and factory-tested, ensuring sealing and low-noise performance, reducing on-site failure risks. If a cable-less version is necessary, strictly follow Meggitt's recommended cable types and installation procedures.

• 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. In this case, the 015 version is the necessary choice.

• 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).

4. Compatibility Notes with Newer Models

The CA280 series may later introduce hardware revision versions (e.g., different suffixes for 144-280-000-xxx), 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 connector type is the same (7/16"-27UNS-2A).

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