CE620 444-620-000-111-A1-B500-C01 Piezoelectric Accelerometer

The CE620 444‑620‑000‑111‑A1‑B500‑C01 is a high‑sensitivity piezoelectric accelerometer with integrated electronics from Meggitt’s renowned vibro‑meter® product line, specifically designed for general‑purpose vibration monitoring in harsh industrial environments where exceptional low‑level signal resolution and measurement flexibility are required. This standard, non‑Ex version features a sensitivity of 500 mV/g, making it ideal for capturing low‑amplitude vibrations on large, slow‑speed machinery, precision equipment, and structural components where every micro‑g of vibration carries critical diagnostic information. The sensor is supplied in a sensor‑only configuration, allowing the user to choose from a comprehensive range of cable assemblies to match the specific environmental, mechanical, and thermal demands of the installation.

The CE620 444‑620‑000‑111‑A1‑B500‑C01 is an industry‑standard IEPE (Integrated Electronics Piezo Electric) sensor that requires a constant current power supply (2 to 10 mA) and operates from a 22 to 28 VDC supply. It provides a low‑impedance voltage output with a nominal bias voltage of 10 VDC, which carries the AC vibration signal superimposed on the DC level. The integrated electronics incorporate an internal shield and are galvanically isolated from the sensor case, ensuring exceptional noise immunity, reduced ground‑loop interference, and stable bias‑voltage performance even in electrically noisy industrial environments.

The sensor is housed in a hermetically sealed stainless‑steel case (AISI 316L) with an IP68 protection rating, offering full protection against dust, prolonged water immersion, and a wide range of industrial contaminants. The rugged, circular MIL‑C‑5015‑105L‑4P connector features a threaded coupling and keyway, providing a secure, vibration‑proof interface that mates with standard MIL‑C/DTL‑5015 type connectors used on Meggitt’s recommended cable assemblies. The sensor‑only format gives the user the freedom to choose cables with different insulations (RADOX®, Teflon® FEP, or polyurethane), overbraids, and protection tubes, optimising the measurement chain for the specific thermal, mechanical, and chemical challenges of each installation.

With a frequency response of ±5 % from 0.2 Hz to 3.7 kHz, a nominal resonant frequency of 15 kHz, and a dynamic range of ±16 g, the CE620 444‑620‑000‑111‑A1‑B500‑C01 is perfectly matched to low‑amplitude, low‑to‑moderate frequency monitoring applications. Its temperature range of –55 °C to 90 °C ensures reliable operation in a wide variety of environments, while the extremely low noise floor (down to 2 μg/√Hz at higher frequencies) and outstanding electromagnetic immunity make it the sensor of choice for precision condition monitoring and predictive maintenance programmes where early fault detection is paramount.

This product introduction provides a comprehensive description of the CE620 444‑620‑000‑111‑A1‑B500‑C01, including key features, applications, detailed technical specifications in tabular form, installation guidelines, ordering information, and available accessories. All information is derived from the official Meggitt data sheet (CE620, 2022) and reflects the company’s commitment to engineering excellence and customer support.

Key Features and Benefits

High Sensitivity for Low‑Level Measurements – With a sensitivity of 500 mV/g ±5 %, the CE620 444‑620‑000‑111‑A1‑B500‑C01 provides a very strong output signal for low‑amplitude vibrations (e.g., bearing wear, structural resonances, micro‑movements), minimising the need for external amplification and improving signal‑to‑noise ratio. This is essential for early fault detection and predictive maintenance.

Optimised Dynamic Range – The dynamic range of ±16 g is perfectly matched to low‑amplitude monitoring applications, ensuring that the sensor operates within its linear range for most condition monitoring scenarios while providing excellent resolution.

Extended Low‑Frequency Response – The sensor offers a flat frequency response of ±5 % from 0.2 Hz to 3.7 kHz, with a –3 dB point at 0.2 Hz, enabling accurate measurement of ultra‑slow machinery, such as large hydro turbines and wind turbine main shafts, where low‑frequency vibrations are dominant.

Ultra‑Low Noise – The residual electrical noise is exceptionally low, with spectral density as low as 2 μg/√Hz at 10 Hz and above, ensuring clear detection of the smallest vibration signals. The internal shielding and isolated electronics further suppress electromagnetic interference.

Integrated Electronics (IEPE) – The built‑in charge‑to‑voltage converter eliminates the need for an external charge amplifier. The 2‑wire interface carries both power and signal, simplifying cabling and reducing system cost. The sensor operates with a constant current of 2 to 10 mA and a supply voltage of 22 to 28 VDC.

Ground‑Isolated Case with Internal Shield – The sensor case is electrically isolated from the signal ground, with a minimum isolation resistance of 100 MΩ, preventing ground loops. An internal shield further enhances noise rejection, ensuring clean signal transmission even when mounted on grounded metal structures.

Rugged IP68 Stainless‑Steel Construction – The hermetically sealed AISI 316L stainless‑steel housing provides IP68 protection, making the sensor impervious to dust, water immersion, and corrosion. This ensures long‑term reliability in the harshest industrial environments, including offshore, chemical, and outdoor installations.

Wide Operating Temperature Range – The CE620 444‑620‑000‑111‑A1‑B500‑C01 operates continuously from –55 °C to 90 °C, with a temperature sensitivity deviation that remains within tight limits, ensuring stable performance across a broad range of thermal conditions.

High Shock and Vibration Tolerance – With a continuous vibration limit of 500 g peak and a shock limit of 5000 g peak, the sensor withstands severe mechanical transients without damage, ensuring survivability in demanding machinery environments.

Low Base Strain Sensitivity – The base strain sensitivity is only 0.0002 g peak/με, minimising measurement errors caused by mounting surface deformation, a common issue in thin‑walled or flexible structures.

Sensor‑Only Flexibility – The sensor‑only format (C01 option) allows the user to select from a variety of cable assemblies (EC318, EC319, EC622, EC632) with different cable materials, overbraids, and protection tubes, tailoring the installation to specific thermal, chemical, and mechanical requirements.

Factory Calibration – Each unit is dynamically calibrated at the factory; no subsequent calibration is required under normal use, reducing maintenance costs.

CE Marked and RoHS Compliant – The sensor meets European Union EMC (2014/30/EU) and RoHS (2011/65/EU) requirements, ensuring global acceptance.

Applications

The CE620 444‑620‑000‑111‑A1‑B500‑C01 is ideally suited for vibration monitoring applications where high sensitivity is required for low‑amplitude signals, including:

• Large Slow‑Speed Machinery – Monitoring of bearings, journals, and structural vibrations on large turbines, hydroelectric generators, wind turbine main shafts, and gearboxes where vibration levels are inherently low and early detection of bearing defects is critical.

• Precision Equipment – Vibration analysis of machine tools, spindles, and high‑speed milling machines to detect tool wear, imbalance, and bearing defects at early stages.

• Structural Health Monitoring – Measurement of low‑level vibrations on bridges, building foundations, and heavy structures to assess dynamic characteristics and detect fatigue cracks.

• Pumps and Compressors – Monitoring of low‑frequency pulsations and bearing wear in centrifugal pumps, reciprocating compressors, and vacuum pumps where sensitivity is crucial.

• Test and Measurement – Laboratory and field testing for modal analysis, shock response, and vibration qualification where high output is beneficial.

• Automotive and Aerospace Testing – Vibration measurement on test rigs, engine mounts, and airframe components where low‑amplitude signals need to be captured with high fidelity.

• General Industrial Condition Monitoring – Any rotating or reciprocating machinery in factories, power plants, and processing facilities where low‑level vibration signals must be reliably detected for predictive maintenance.

Detailed Description of the Sensor‑Only Standard Version (444‑620‑000‑111‑A1‑B500‑C01)

The CE620 444‑620‑000‑111‑A1‑B500‑C01 is the standard, non‑Ex, sensor‑only variant of the CE620 family, featuring a high sensitivity of 500 mV/g and a temperature range of –55 °C to 90 °C (order option A1). It is designed for general‑purpose vibration monitoring in ordinary industrial environments where the user requires the flexibility to choose the most appropriate cable assembly for the specific installation and where low‑amplitude signals are predominant. The sensor is built around a piezoelectric sensing element that generates an electrical charge proportional to acceleration. The integrated electronics package, housed within the sensor casing, converts this charge into a low‑impedance voltage signal, which is transmitted over a two‑wire shielded cable.

The sensor’s output is a voltage signal consisting of a DC bias voltage (nominal 10 V for the 500 mV/g version) and an AC vibration component superimposed on it. The bias voltage provides a reference level and also powers the internal electronics. The sensor requires an external constant current power supply (IEPE conditioner) that provides a current source between 2 and 10 mA (typically 4 mA) and a DC voltage of 22 to 28 V. The current source is connected in series with the signal line, and the AC vibration signal is measured across a load resistor in the monitoring system, typically extracting the AC component via a high‑pass filter. The low‑frequency cutoff is determined by the time constant of the coupling capacitor and load resistor; the sensor itself has a –3 dB point at 0.2 Hz, making it exceptionally well‑suited for very low‑frequency measurements.

The ground‑isolated design, with an internal shield, ensures that the sensor case and mounting base are electrically isolated from the signal ground with a minimum isolation resistance of 100 MΩ. This is critical in industrial settings where multiple earth points can create ground loops, leading to measurement errors and noise. The internal shield further attenuates electromagnetic interference, ensuring clean signal transmission even in environments with strong electrical fields.

The mechanical construction features a hermetically welded stainless‑steel housing (AISI 316L) that provides IP68 protection against dust and prolonged water immersion. The sensor’s connector is a rugged, circular 2‑pin MIL‑C‑5015‑105L‑4P type with a threaded coupling and keyway, ensuring a secure, vibration‑resistant interface that prevents accidental disconnection. The connector mates with standard MIL‑C/DTL‑5015 type connectors used on Meggitt’s recommended cable assemblies.

The mounting interface is a 1/4″‑28 UNF‑2A external thread, and the sensor is supplied with two adapter studs: one 1/4″‑28UNF to 1/4″‑28UNF and one 1/4″‑28UNF to M8×1.25. These allow direct mounting onto common machine threads. The recommended mounting torque for the stud is 2.4 N·m (1.8 lb‑ft), ensuring proper coupling and optimal high‑frequency response.

The CE620 444‑620‑000‑111‑A1‑B500‑C01 is factory‑calibrated at a reference frequency and amplitude, with the sensitivity verified to be within ±5 % of the nominal 500 mV/g. The calibration is performed using a known acceleration standard, and no further calibration is required during the sensor’s lifetime under normal operating conditions. However, periodic verification (e.g., every 2‑5 years) is recommended for critical safety‑related applications.

This sensor‑only version (C01 option) does not include a cable, allowing the user to select from a range of cable assemblies (EC318, EC319, EC622, EC632) that differ in cable material (RADOX®, Teflon® FEP, polyurethane), protection (flexible stainless‑steel hose, overbraid), and environmental rating (standard, splashproof, higher temperature). This flexibility ensures that the measurement chain can be optimised for the specific thermal, chemical, and mechanical demands of each installation, making the CE620 444‑620‑000‑111‑A1‑B500‑C01 a versatile choice for a wide range of industrial applications where high sensitivity is paramount.

It should be noted that, according to the ordering information in the data sheet, Ex versions of the CE620 with 500 mV/g sensitivity are not available; only 100 mV/g Ex versions are offered. Therefore, the CE620 444‑620‑000‑111‑A1‑B500‑C01 is strictly a standard (non‑hazardous area) sensor.

Installation and Mounting Guidelines

Proper installation is essential to achieve the specified performance from the CE620 444‑620‑000‑111‑A1‑B500‑C01. The following guidelines are based on Meggitt’s recommended practices:

• Mounting Surface Preparation – The mounting surface should be flat, smooth, and clean. Any burrs, paint, or corrosion must be removed to ensure full contact between the sensor base (or adapter stud) and the machine surface. A surface finish of 1.6 µm (63 µin) or better is recommended for optimal high‑frequency response.

• Adapter Stud Selection – The sensor is supplied with two adapter studs: one 1/4″‑28UNF (straight) and one M8×1.25. Choose the stud that matches the threaded hole in the machine or the mounting block. If a different thread is required (e.g., M6), optional mounting adaptors (MA122_012 or MA122_021) are available.

• Torque Application – Screw the chosen stud into the sensor base (using the 1/4″‑28 UNF‑2A thread) and tighten to the recommended torque of 2.4 N·m (1.8 lb‑ft). Then mount the assembled sensor onto the machine surface, applying the appropriate torque for the machine thread (e.g., 15‑20 N·m for M8, but refer to the machine manufacturer’s recommendations). Do not over‑torque, as this may damage the threads or the sensor housing.

• Orientation and Alignment – The sensor is sensitive along its principal axis (marked on the housing). Align the sensor such that the principal axis coincides with the direction of the vibration to be measured (axial, radial, or tangential). Refer to the installation manual for detailed orientation diagrams.

• Cable Assembly Selection and Connection – As this is a sensor‑only version, select a suitable cable assembly from the available options (EC318, EC319, EC622, EC632). The cable assembly will have a matching MIL‑C/DTL‑5015 type connector that mates with the sensor’s MIL‑C‑5015‑105L‑4P connector. Ensure the connector is fully engaged and the threaded coupling is tightened to prevent loosening under vibration. Route the cable with a minimum bend radius to avoid stress and internal damage. Secure the cable at intervals using P‑clips or cable ties, but avoid over‑tightening. For environments with high moisture, chemicals, or mechanical abrasion, use cables with protection tubes (e.g., EC318 with flexible stainless‑steel hose or EC319 with sealed hose).

• Electrical Connections – The sensor requires a constant current power supply. Connect the positive lead (Pin A+, usually red wire) to the current source positive, and the negative lead (Pin B‑, usually white or common) to the return/signal ground. The supply voltage must be between 22 and 28 VDC, and the current must be between 2 and 10 mA. The signal is measured as the AC voltage on the bias level (typically 10 V) via a decoupling capacitor in the monitoring system. Ensure the monitoring system provides the appropriate high‑pass filtering (usually with a cutoff frequency at or below 0.2 Hz for the sensor’s specified response). The cable shield should be grounded at one end (typically at the monitoring system) to minimise electromagnetic interference.

• Grounding – The sensor’s base is isolated from the signal ground, so the mounting surface can be at any potential without affecting the signal. However, the cable shield should be grounded at one end (usually at the monitoring system) to minimise electromagnetic interference. Follow the grounding practices recommended in the system’s installation manual.

• Thermal Considerations – The sensor is rated for continuous operation up to 90 °C. If the mounting surface exceeds this temperature, use a thermal insulating adaptor (e.g., MA122_021) or mount the sensor remotely with an extension rod. The connector and cable must also be rated for the expected temperature; for high‑temperature applications, use cables with suitable insulation such as RADOX® or Teflon® FEP.

• Protection from Physical Damage – In harsh environments, protect the sensor and cable from impacts, abrasion, and chemical attack. Use protective covers or conduits if necessary. The IP68 rating ensures the sensor is dust‑tight and protected against water immersion, but mechanical protection is still recommended.

• Hazardous Area Precautions – This standard version (A1) is not Ex‑certified; therefore, it must not be used in potentially explosive atmospheres. For such areas, use the Ex‑certified versions (option A2, but note that 500 mV/g Ex versions are not available).

Commissioning and Verification

After installation, the CE620 444‑620‑000‑111‑A1‑B500‑C01 should be verified using a known vibration source (e.g., a portable shaker or a reference accelerometer) or by comparing with a known good sensor. The bias voltage should be measured to confirm it is approximately 10 V (within ±1 V). The AC signal should be checked for proper sensitivity; a known acceleration level (e.g., 1 g at 80 Hz) should produce the expected output (500 mV/g). Also verify that the signal is free from excessive noise and that the low‑frequency cutoff is appropriate for the intended measurement. For long‑term monitoring, regular system checks during routine maintenance are recommended.

Accessories

A range of accessories is available to complement the CE620 444‑620‑000‑111‑A1‑B500‑C01, including cable assemblies, adaptor studs, and mounting adaptors. The sensor is supplied with two adaptor studs; optional items are listed below.

Note: Cable length must be specified when ordering any cable assembly. For EC31x cables, any length can be specified; for EC6x2 cables, standard lengths are 2, 5, 10, 15, 20, or 30 m (ordering option codes L2000, L5000, L10000, etc.). Refer to the cable assembly product drawings for further information.

Disposal and Environmental Compliance

At the end of its service life, the CE620 444‑620‑000‑111‑A1‑B500‑C01 must be disposed of in accordance with local environmental regulations. The sensor contains stainless steel, electronic components, and piezoelectric materials. In the European Union, the Waste Electrical and Electronic Equipment (WEEE) Directive applies – separate collection and recycling are mandatory. Meggitt supports environmentally responsible disposal and can provide guidance on proper recycling channels.