8 RMS: advantages/disadvantages Positive:StableRepeatableSuited for trendingNegative:Insensitive to short duration eventsSo not suited to early stage impact detectionWelcome everyone to the webinar and introduce the 3 key takeaways.
9 Max RMS: advantages/disadvantages Positive:Stable and repeatableComparison with RMS: steady or varying signalSuited for trendingNegative:Insensitive to early stage impact detectionWelcome everyone to the webinar and introduce the 3 key takeaways.
10 What is Peak? The highest value detected in the time signal Physical unit used: dBµVThe Sampling Rate is 8K.
11 Peak : advantages/disadvantages Positive:Very sensitive to any changeSuited for impact detectionNegative:Not going to be repeatable, by the very nature of infrequent transientsTrends difficult to interpretWelcome everyone to the webinar and introduce the 3 key takeaways.
12 What is Crest Factor? The Peak-to-RMS ratio Crest Factor = Peak / RMS No physical unit – it is a numeric ratioIndicates how Peaky the signal is or how many impacts/RMS
13 What is Crest Factor? RMS value is 20dBµV Peak is 40dBµV Crest Factor could be expressed in dB’s40-20=20dBCrest Factor is expressed in linear numbersCrest Factor is 1040dBµV = 100µV, 20dBµV = 10µVCrest Factor is 100/10= 10
14 Condition indicators A guide to choosing RMS Max RMS Peak Crest FactorLeakSteam trapsLubricationMechanicalElectricalWelcome everyone to the webinar and introduce the 3 key takeaways.
15 Condition indicators A comparison guide Positive Negative RMS Stable RepeatableTrendingInsensitive to short duration eventsNot suited for early stage bearing failureMax RMSSteady or fluctuating signal (vs. RMS)Peak and Crest FactorVery sensitive to any changeSuited for bearing failureNot stable and repeatable Not suited for trendingWelcome everyone to the webinar and introduce the 3 key takeaways.
16 Benefits Combining the 4 condition indicators: Better view of machinery health or performance (steam traps, mechanical)Better evaluation of the failure severity (lubrication, mechanical, traps)Better diagnosis capabilities (lubrication vs bearing failure)Early stage detection (mechanical)Welcome everyone to the webinar and introduce the 3 key takeaways.
17 Condition indicators and UAS UAS handles each indicator separatelySelect whichever you want for trend displayAlarms are set up individually for each(3 Absolute, 4 Relative, 2 Safe) x 4 = 36 alarms
18 Condition indicators and UAS Simplicity for those who wantElaborate for those who needWelcome everyone to the webinar and introduce the 3 key takeaways.
20 Slow Speed Condition Monitoring Rotating MachinerySlow Speed Condition MonitoringDifficult with some technologiesUltrasound does not need 1 minute
21 Ferris Wheel Feng Shui A Singapore Flyer Spindle bearing measurements taken one month after rotational direction changed (Feng Shui)37 minutes for one rotation RPMA
22 Special Applications – Hoist Bearing Rotating MachinerySpecial Applications – Hoist BearingDoesn’t operate long enough for some tech.14 RPM but for 10 or 20 seconds onlyBPFI expected at 2.88Hz/173CPM
23 Time SignalTime SignalImpacts can be seen clearly
24 Expand any area of this time signal Apply a periodic cusor You get a repetition frequency of 346cpm2x the inner race defect frequency (173cpm)
25 Inner Race Defect Discovered Rotating MachineryInner Race Defect DiscoveredSpalling across the length of the raceway
26 Bearing failure example Healthy bearing:RMS = 24.4 dBµV, Peak = 43.1 dBµV, CF = 8.6Welcome everyone to the webinar and introduce the 3 key takeaways.
27 Bearing failure example Defective bearing:RMS = 47.7 dBµV, Peak = 75.4 dBµV, CF = 21.9Welcome everyone to the webinar and introduce the 3 key takeaways.
28 What’s the problem? Over lubrication is A huge killer of bearings Consumes far too much greaseConsumes far too much timeReduces reliability
29 Applications Lubrication: Lubrication is friction Correctly greased: regular and pleasant signal (low RMS value)Under or over greased: friction, and so signal is increasingRMS is the suited indicator, throw in Peak to detect possible early stage damageWelcome everyone to the webinar and introduce the 3 key takeaways.
35 Using an accelerometer VibrationUltrasoundImagingThermalOil AnalysisMotor Current Analysis
36 Keeping it simple The 270 has IR temperature measurement But it is not an IR cameraThe 270 has vibration measurementBut it is not a vibration data collectorThat’s not the intention
37 Using an accelerometer Adds one extra tool to the powerful SDT270Means that users can make diagnosis that bit easierDon’t need to go back to office to change toolsDon’t need to ask somebody else to do it
38 What can I measure? Velocity in ips or mm/s 10-1,000Hz Acceleration in g 10-10,000HzRMS and Peak calculatedDynamic measurement (Time) of both now possible with the Raw option instead of Ht.All options controlled inside UAS Sensor OptionsSupports 100mV/g ONLY
43 Valve Inspections1. Do a comparison method before and after the valve. OR 2. Contact the valve and listen.
44 Valves and Hydraulics Find internal leakage and passing valves Perform inspections without disassemblySave hours or even days from complicated repairsUltrasonic Inspection of Hydraulics:Place contact sensor on valve body and wait for system to cycle.Ultrasound will tell you that the valve is passing or stuck in shut position.
45 Valve Body Inspection Checking valve for flow Upstream and downstream Works for any gas or liquid
46 Valve InspectionsIdentify the difference between a closed and 10% open 60cm bypass recycle valveDynamic measurements captured downstreamTime signals identically scaledValve closedValve opened 10%
47 Steam Trap example Good trap: Max RMS (43.3 dBµV) is higher than RMS (29.7 dBµV) Peak (51.7 dBµV)RMSMax RMSWelcome everyone to the webinar and introduce the 3 key takeaways.
48 Trap example Failed closed: RMS is low (9.4 dBµV) Max RMS (11.5 dBµV) is close to RMSRMSMax RMSWelcome everyone to the webinar and introduce the 3 key takeaways.
49 Trap example Failed open: RMS is high (39.5 dBµV) Max RMS is close to RMS (41.9 dBµV)RMSMax RMSWelcome everyone to the webinar and introduce the 3 key takeaways.