CE620 444-620-000-011-A1-B500 Piezoelectric Accelerometer

The CE620 444‑620‑000‑011‑A1‑B500 is a high‑sensitivity piezoelectric accelerometer with integrated electronics from Meggitt’s distinguished vibro‑meter® product line, specifically designed for general‑purpose vibration monitoring in harsh industrial environments where superior low‑level signal resolution is required. This standard version, featuring a sensitivity of 500 mV/g, is intended for use in non‑hazardous (ordinary) areas and offers an exceptional dynamic range of ±16 g, making it ideal for measuring low‑amplitude vibrations on large, slow‑speed machinery, precision equipment, and structures where high sensitivity is paramount. The sensor delivers a voltage output signal that is proportional to acceleration, with a high signal‑to‑noise ratio, enabling accurate detection of subtle changes in machine health.

The CE620 444‑620‑000‑011‑A1‑B500 incorporates a piezoelectric sensing element with built‑in integrated electronics (IEPE – Integrated Electronics Piezo Electric) that convert the charge generated by the element into a low‑impedance voltage signal. This signal is transmitted over a standard 2‑wire shielded cable, which simultaneously provides power to the sensor and carries the AC vibration signal superimposed on a DC bias voltage. The sensor requires a constant current power supply (typically 2 to 4 mA) and operates from an 18 to 30 VDC supply, making it compatible with most industrial monitoring systems. The integrated electronics are ground‑isolated from the case, ensuring excellent noise immunity and stable bias voltage performance, even in electrically noisy environments.

The CE620 444‑620‑000‑011‑A1‑B500 is housed in a rugged, hermetically sealed stainless‑steel case with an IP67 protection rating, providing full protection against dust, water, and other contaminants. Its compact design and versatile mounting options (with supplied adaptor studs for M8×1.25, M8×1, and 1/4‑28UNF threads) enable easy installation on a wide range of machinery surfaces. The sensor features a 2‑pin MIL‑C/DTL‑5015 type connector, which mates with a variety of cable assemblies to suit different environmental conditions.

With a frequency response of 2 Hz to 10 kHz (±5 %) and a nominal resonant frequency of 18 kHz, the CE620 444‑620‑000‑011‑A1‑B500 captures both low‑frequency machinery dynamics and high‑frequency gearmesh and blade‑pass signatures. Its temperature range of –55 °C to 140 °C, combined with a temperature response deviation of only ±5 % over the full range, ensures reliable operation in extreme thermal environments. The 500 mV/g sensitivity provides a significant output level for low‑amplitude signals, reducing the need for additional amplification and improving measurement accuracy.

This product introduction provides a comprehensive description of the CE620 444‑620‑000‑011‑A1‑B500, 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 old version, 2020) 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 444‑620‑000‑011‑A1‑B500 provides a strong output signal for low‑amplitude vibrations (e.g., bearing wear, structural resonances), minimising the need for external amplification and improving signal‑to‑noise ratio. This makes it ideal for predictive maintenance on large, slow‑speed machinery and precision applications.

Integrated Electronics (IEPE) – The built‑in charge‑to‑voltage converter eliminates the need for an external charge amplifier, providing a low‑impedance voltage output compatible with standard data acquisition systems. The 2‑wire interface simplifies cabling and reduces installation costs.

Limited Dynamic Range Optimised for Sensitivity – The dynamic range of ±16 g (for the 500 mV/g version) 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.

Excellent Frequency Response – A flat response of ±5 % from 2 Hz to 10 kHz, combined with a nominal resonant frequency of 18 kHz, enables accurate measurement of slow‑speed machinery, high‑speed turbines, and gearbox vibrations.

Ground‑Isolated Case – The sensor’s base and case are electrically isolated from the signal ground, preventing ground loops and ensuring clean signal transmission in electrically noisy industrial environments. This feature also simplifies installation on grounded structures.

Wide Operating Temperature Range – The CE620 444‑620‑000‑011‑A1‑B500 operates continuously from –55 °C to 140 °C, with minimal temperature‑induced sensitivity deviation (±5 % typical), making it suitable for applications ranging from cryogenic pumps to hot gas turbine casings.

Robust IP67 Protection – The hermetically sealed stainless‑steel housing provides full protection against dust, water immersion, and a wide range of industrial contaminants, ensuring long‑term reliability in harsh environments.

Low Electrical Noise – Residual electrical noise is only 0.1 mg (maximum), ensuring high signal‑to‑noise ratio for precise low‑level vibration measurements. Electromagnetic sensitivity is exceptionally low at 50 μg/gauss.

Reversed Polarity Protection – The sensor is protected against accidental reversed power connections, preventing damage during installation or maintenance.

Easy Mounting – Supplied with three adapter studs (M8×1.25, M8×1, and 1/4‑28UNF), the sensor can be mounted directly onto a variety of thread sizes without additional adaptors. The external thread (1/4‑28UNEF‑2A or 5/8‑24UNEF‑2A) ensures secure attachment.

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 CE620 444‑620‑000‑011‑A1‑B500 meets European Union environmental and safety standards, ensuring global acceptance.

Applications

The CE620 444‑620‑000‑011‑A1‑B500 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.

• 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 Standard Version (444‑620‑000‑011‑A1‑B500)

The CE620 444‑620‑000‑011‑A1‑B500 is the standard, non‑Ex variant of the CE620 family, featuring a high sensitivity of 500 mV/g and a wide temperature range of –55 °C to 140 °C (order option A1). It is designed for general‑purpose vibration monitoring in ordinary industrial environments where high sensitivity is required to capture low‑amplitude vibrations. 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 12 V) 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 (often referred to as an IEPE conditioner) that provides a current source between 0.5 and 8 mA (typically 2 to 4 mA) and a DC voltage of 18 to 30 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 (cutoff frequency determined by the system).

The ground‑isolated design ensures that the sensor case and mounting base are electrically isolated from the signal ground. This is critical in industrial settings where multiple earth points can create ground loops, leading to measurement errors and noise. The isolation also allows the sensor to be mounted directly on grounded metal structures without affecting signal integrity.

The mechanical construction features a hermetically welded stainless‑steel housing that provides IP67 protection against dust, water immersion, and corrosion. The sensor’s connector is a rugged, circular 2‑pin MIL‑C/DTL‑5015 type, which provides a secure, vibration‑resistant interface for cable connections. A range of cable assemblies is available, including standard ETFE cables, cables with metallic overbraid, and flexible RADOX® cables with or without protection tubes, to suit different environments (oil, high temperature, mechanical abrasion).

The mounting interface is an external thread – either 1/4‑28UNEF‑2A or 5/8‑24UNEF‑2A, depending on the specific version. The supplied adapter studs allow conversion to common metric threads (M8×1.25 and M8×1) as well as imperial 1/4‑28UNF, providing flexibility for mounting on various machine surfaces. The sensor is designed to be mounted directly to the machine surface using a stud, with a recommended torque to ensure proper coupling and high‑frequency response.

The CE620 444‑620‑000‑011‑A1‑B500 is factory‑calibrated at a reference frequency (typically 100 Hz) 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 standard version does not carry Ex certification, making it suitable for use in non‑hazardous areas. For installations in potentially explosive atmospheres, Ex‑certified versions (with order option A2 and a different part number) are available, featuring intrinsic safety (Ex ia) and reduced temperature range (–55 to 115 °C). The CE620 444‑620‑000‑011‑A1‑B500 is therefore the optimal choice for ordinary industrial applications where high sensitivity and maximum temperature capability are required.

The high sensitivity of 500 mV/g provides a significant output level for low‑amplitude signals, making it ideal for monitoring large, slow‑speed machinery (e.g., hydro turbines, wind turbines) where vibration levels are typically below 10 g. The dynamic range of ±16 g ensures that the sensor remains linear for the majority of condition monitoring applications, while the excellent resolution allows detection of subtle changes in bearing condition, imbalance, or structural resonances.

Installation and Mounting Guidelines

Proper installation is essential to achieve the specified performance from the CE620 444‑620‑000‑011‑A1‑B500. 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 three adapter studs: one M8×1.25, one M8×1, and one 1/4‑28UNF. Choose the stud that matches the threaded hole in the machine or the mounting block. If using a different thread, optional mounting adaptors (e.g., MA122 with M6 thread) are available.

• Torque Application – Screw the chosen stud into the sensor base (using the 1/4‑28UNEF‑2A or 5/8‑24UNEF‑2A thread) and tighten to the recommended torque (typically 7‑10 N·m for the stud, or as specified in the accessories data sheet). 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). 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 Routing and Connector – The sensor uses a 2‑pin MIL‑C/DTL‑5015 type connector. Mating connectors are available in various cable assemblies (EC602, EC612, EC318, EC319). Ensure the cable is routed with a minimum bend radius (typically >25 mm) 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 or mechanical abrasion, use cables with protection tubes (e.g., EC319 with sealed protection tube).

• Electrical Connections – The sensor requires a constant current power supply. Connect the positive lead (Pin A+) to the current source positive, and the negative lead (Pin B‑) to the return/signal ground. The supply voltage must be between 18 and 30 VDC, and the current must be between 0.5 and 8 mA. The signal is measured as the AC voltage on the bias level (typically 12 V) via a decoupling capacitor in the monitoring system. Ensure the monitoring system provides the appropriate high‑pass filtering (usually with a cutoff frequency of 0.5 to 1 Hz for the sensor’s specified response).

• 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 140 °C. If the mounting surface exceeds this temperature, use a thermal insulating adaptor (e.g., MA133 available for other sensor families) 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 (e.g., RADOX® 125 or metallic overbraid).

• 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 IP67 rating ensures the sensor is dust‑tight and protected against water immersion, but mechanical protection is still recommended.

• Hazardous Area Precautions – This standard version is not Ex‑certified; therefore, it must not be used in potentially explosive atmospheres. For such areas, use the Ex‑certified versions (option A2) and follow the specific installation requirements of the Ex certificates.

Commissioning and Verification

After installation, the CE620 444‑620‑000‑011‑A1‑B500 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 12 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 444‑620‑000‑011‑A1‑B500, including:

Note: Cable length must be specified when ordering any cable assembly. For the EC318 and EC319, different lengths are available – contact Meggitt for custom lengths.

Disposal and Environmental Compliance

At the end of its service life, the CE620 444‑620‑000‑011‑A1‑B500 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.