plus SKF Vibration Pen CMVP 40 (in/s) eq. Peak CMVP 50 (mm/S) RMS Overall Vibration and Acceleration Enveloping Overview A Multi-Parameter approach to condition monitoring provides two different methods for monitoring machinery condition. This allows for early detection of specific machinery problems and provides more ways to measure changes in machinery condition. plus The SKF Vibration Pen is a Multi-Parameter vibration monitoring tool capable of measuring vibration (caused by rotational and structural problems like imbalance, misalignment, looseness, etc.), and capable of measuring vibration in higher frequencies (caused by rolling element bearing or gear mesh problems). Multi-Parameter Monitoring is the most thorough and effective method for monitoring bearing plus and machinery condition. The Vibration Pen tool’s Multi-Parameter approach provides accurate and reliable data upon which to base maintenance decisions and promotes early detection, confirmation, and accurate trending of bearing and machinery problems. plus SKF Vibration Pen CMVP 40 (in/s) eq. Peak / CMVP 50 (mm/s) RMS www.skf.com/cm 2 For example, suppose a rolling element bearing has a defect Functional Description on its outer raceway. Each rolling element strikes the defect plus When performing measurements, the Vibration Pen tool’s as it passes the defect, causing a small, repetitive vibration sensor input signal is processed to produce two different signal. This vibration signal is of such low amplitude that, measurements for each machinery POINT, Overall Vibration under normal ISO vibration monitoring, it is lost in the and Enveloped Acceleration. machine’s other rotational and structural noise. plus The Vibration Pen tool’s LCD simultaneously displays both Envelope detection filters out low frequency rotational measurement values. Depending on the type and location signals, then enhances the high frequency defect signals to of the machinery component being measured, either or both focus on repetitive events in the 10 kHz to 30 kHz frequency readings may be of interest. range, and provides an averaged peak value for early detection of bearing and gear mesh problems. OVERALL VIBRATION (ISO* 10816, Part 1-6) Low Frequency Vibration (10 Hz to Enveloped acceleration measurements do not 1 kHz) detect rotational or structural vibration caused by Overall velocity vibration occurring in the 10 Hz to 1 kHz imbalance, misalignment, looseness, etc. frequency band is considered the best operating parameter for judging rotational and structural problems like imbalance, Easy Operation resonance, misalignment, looseness, and stress applied to plus Vibration Pen readings are easily performed, simply: components. plus • Turn the Vibration Pen on. plus Many machinery problems may cause excessive overall • Press the Vibration Pen tool’s sensor tip against your vibration. Mechanical looseness, imbalance, soft foundation, machinery measurement POINT. misalignment, rotor bow, resonance, eccentricity, bad belts, • Wait for the readings to stabilize, and record the or lost rotor vanes can all be measured with overall ISO* measurement values. vibration measurements. Easy Evaluation Measuring the overall vibration of a machine or component, plus The Vibration Pen tool’s front-panel LCD simultaneously or the structure of a machine, and comparing the measured shows overall velocity vibration readings in mm/s RMS value to the machine’s normal value (or to ISO 10816 (CMVP 50) or in in/s eq. Peak (CMVP 40), and acceleration standards) indicates machinery health and condition changes. E enveloping readings in g (“E” indicating Enveloped Overall vibration is not an indicator of bearing or gear acceleration). mesh problems that typically occur in higher frequency plus The SKF Vibration Pen severity card provides quick ranges. reference for ISO Standard 10816 overall velocity vibration ENVELOPED ACCELERATION comparisons. Bearing/Gear mesh Frequency Vibration (10 kHz to 30 General Severity Level Guidelines kHz) When considering severity levels, one should always Enveloped Acceleration measurements measure the high be aware that even standards can only provide general frequency repetitive vibration signals typically caused by guidelines to determine initial alarm settings. At no time bearing and gear mesh problems. should such guidelines substitute for experience and good Envelope detection is very useful in rolling element bearing judgement. The most reliable method of determining alarm and gear mesh analysis where a low amplitude, repetitive settings is to trend vibration readings over time, establish vibration signal may be hidden by the machine’s rotational baseline values and alarm settings above baseline values. and structural vibration noise. Vibration Measured In Velocity For velocity vibration, ISO standards like ISO 10816, First Edition 1995 or VDI 2056 guidelines are generally accepted. ISO 10816 with the title ‘Mechanical vibration – Evaluation of machine vibration by measurements on non-rotating parts’ consists of six parts. Part 1 (10816-1) determines general * ISO (International Organization for Standardization) guidelines and are superseded by the following, more explicit plus SKF Vibration Pen CMVP 40 (in/s) eq. Peak / CMVP 50 (mm/s) RMS www.skf.com/cm 3 Table 1. Vibration Severity Chart ISO 10816-2. parts of ISO 10816, like part 2 (10816-2) for Land-based steam turbines and generators in excess of 50 MW with ISO 10816-2 Steam Turbines and Generators normal operating speeds of 1500 r/min, 1800 r/min, 3000 r/min and 3600 r/min. Velocity Speed (rpm) CMVP 40 CMVP 50 The severity chart shown in Table 1, is in accordance with in/sec eq. mm/sec 1500 or 1800 3000 or 3600 the ISO 10816-2 guidelines. For exceptions to this guideline Peak RMS and for more details, please refer to the ISO 10816-2 DAMAGE OCCURS 0.66 11.8 document itself. 0.56 10.0 Industrial machines with nominal power above 15 kW and 0.47 8.5 nominal speeds between 120 rpm and 15000 rpm when 0.42 7.5 RESTRICTED OPERATION measured in situ are covered by ISO 10816-3. 0.29 5.3 The machines are separated into four different groups: 0.21 3.8 UNRESTRICTED OPERATION GROUP 1 0.16 2.8 Large machinery and electrical machines with shaft height 0.08 1.4 NEWLY COMMISSIONED greater than 315 mm. These machines are normally MACHINERY 0.00 0.0 equipped with sleeve bearings. GROUP 2 Table 2. Vibration Severity Chart ISO 10816-3. Medium-size machines and electrical machines with shaft height in between 160 mm and 315 mm. Machinery Machinery ISO 10816-3 Groups 2 and 4 Groups 1 and 3 These machines are normally equipped Velocity with rolling element bearings and operating Rated Power speeds above 600 rpm. CMVP 40 CMVP 50 Group 1: 300 kW – 50 MW in/sec eq. mm/sec 15 kW – 300 kW Group 3: Above 15 kW Peak RMS GROUP 3 0.61 11.0 Pumps with multivane impeller and with DAMAGE OCCURS separate driver with rated power above 0.39 7.1 15 kW. 0.25 4.5 RESTRICTED OPERATION Machines of this group may be equipped with 0.19 3.5 sleeve or rolling element bearings. UNRESTRICTED 0.16 2.8 OPERATION 0.13 2.3 GROUP 4 Pumps with multivane impeller and with 0.08 1.4 integrated driver. 0.04 0.7 NEWLY COMMISSIONED MACHINERY 0.00 0.0 Machines of this group mostly have sleeve or rolling element bearings. Flexible Foundation Rigid Flexible Rigid SKF Vibration Specifications Vibration Pickup: Piezoelectric plus Pen acceleration integrated sensor (compression type) CMVP 40 Measurement Range: 1 to 55 mm/s (in/s) eq. Peak (RMS) 0.06 to 3.00 in/s (eq. Peak) Tolerance: ± 10% and 2 digits measured CMVP 50 at 80 Hz Frequency Range: (mm/s) RMS Overall Vibration: 10 Hz to 1,000 Hz (Tolerances measured within the frequency range are in accordance with ISO 3945 and 2 digits.) Acceleration Enveloping: 10 kHz to 30 kHz Display: Measurement Value 3.5 digit LCD Display Cycle: Approximately one (1) second Overload Indication: OVER Battery Replacement Indication: BATT Hold Indication: HOLD Power: Two (2) CR2032 lithium batteries Battery Lifetime: 170 mA hours Current consumption Measurement mode: 7.5 mA HOLD mode: 3.0 mA Auto Power Off Function: Power is turned off approximately two minutes after last ON or HOLD operation Ordering Information Dimensions: Height: 0.7” (17.8 mm) plus CMVP 40 (in/s) eq. Peak Vibration Pen Width: 1.2” (30.5 mm) plus CMVP 50 (mm/s) RMS Vibration Pen Length: 6.2” (157.5 mm) Weight: Approximately 2.7 oz. (77 g) with batteries Ambient Operating Conditions: +14 °F to +122 °F (-10 °C to +50 °C) 20% to 90% relative humidity SKF Reliability Systems 5271 Viewridge Court • San Diego, California 92123 USA Telephone: +1 858-496-3400 • FAX: +1 858-496-3531 Web Site: www.skf.com/cm The contents of this publication are the copyright of the publisher and may not be reproduced (even extracts) unless permission is granted. Every care has been taken to ensure the accuracy of the information contained in this publication but no liability can be accepted for any loss or damage whether direct, indirect or consequential arising out of the use of the information contained herein. SKF reserves the right to alter any part of this publication without prior notice. SKF Patents include: #US05854553, #US05845230, #US06489884, #US05679900, #US04768380, #US06199422, #US05992237, #US06202491, #US06513386, #US06275781, #US06633822, #US06006164, #US2003 0178515A1, #US6,789,025, #US6,789,360, #WO 03 048714A1 • SKF is a registered trademarks of the SKF Group. • All other trademarks are the property of their respective owners. CM2081 (Revised 6-06) • Copyright © 2006 by SKF Condition Monitoring, Inc. ALL RIGHTS RESERVED.