Sonic Analysis

Sonic Analysis System – A Non Destructive Testing Technique
Description: Sonic Analysis System is a Non destructive Testing technique to differentiate between the nodularity of Cast iron

Gray cast Iron vs Ductile cast Iron :

  • Compared with grey iron, nodular iron has an absolute advantage in intensity. The max tensile strength of nodular iron is 90k psi, while the max tensile strength of grey iron is only 35k psi.
  • Nodular Irons are generally superior to grey irons, regarding their yield strength. The max yield strength of ductile iron is 40k psi; Grey iron is not very malleable or strong, it fractures easily.
  • Nodular iron is more flexible and elastic than other cast irons. Nodular iron has higher strengths, greater elongation and better resistance to impact than grey iron.

Why Sonic Analysis System?

Sonic Analysis mechanism operates in the sonic frequency range. Every material produces a different frequency sound when struck with a solid object, such as gong. The captured signal is analyzed for all of its signal parameters such as Frequency, Amplitude etc. The process is as follows:

  • A mechanism is used to strike the test object with a predetermined force. This produces a sound of particular frequency and amplitude.
  • This signal is detected by a sensor
  • The detected signal is analyzed for all its data parameters using the software LABVIEW.
  • The detected signal is analyzed for all its data parameters using the software LABVIEW.
  • The software compares the obtained data parameters with the table and generates the appropriate output for further actions

Product Features

  • Capable to differentiate between objects made of different types of Cast Iron such as Ductile Cast Iron and Gray Cast Iron
  • It can be extended to any other type of metallic objects as well with appropriate calibration
  • The end-to-end cycle time is less than 45 seconds. Could be optimized further on case to case basis.
  • User friendly interface for differentiating objects as Pass/Fail
  • Non-destructive test type. No waste of parts for testing purpose
  • This mechanism doesn't use any consumables
  • No replaceable parts due to wear and tear of the measurement system (sensors) as the measurement mechanism is non-contact type
  • Requires very little maintenance

Comparison between Velocity and Sonic Analysis methods

Sl. No. FeatureVelocity MethodSonic Analysis MethodRemarks
1Detection typeContact typeNon-eontact type
2Basis of MeasurementMaterial thickness at the point of measurementMaterial profile
3Operation typeManual
4Inputs needed to perform detectionDistanceNot needed
5Devices needed to perform detection1) Ultrasonic detection device
2) Distance/Thickness measuring device
1) Sonic analysis device
6CalibrationAt regular intervals to ensure proper functioning of the probeOnly once for a given component
7Procudure to perform detection 1) Identify the region to place the probe
2) Measure the thickness and feed this value to the device
3) Apply couplant
4) Place the probe on the couplant
5) Obtain the result
1) Identify the region to strike the component
2) Strike the component
3) Obtain the result
8 Detection limitation 1) Thickness of the object at the point of measurment has to be less than 50mm for a sandard probe (A max of upto 300mm using specialized probes) 2) Need a flat surface for probe placementNot neededThis is the reson why few of the users are not using this guage to defferentiate between Ductile and Gray components. Hence they depend on Manual Sound analysis
9Cycle time3 mins per componentLess than 45 sees per component.Has scope for further improvement upto less than 10 sees per component
10ComsumablesCouplantNot needed
11Replaceable parts due to wear and tearProbeNot needed 1) Transducer (Probe) performance will be degraded by excessive wear at the tip and when transducer (probe) tip bemmes too rough, mncave or otherwise non-flat, operation may become erratk or impossible
2) Severe wear will limit transducer (Probe) life Ref: User manual of Panametria; Ultrasonk predsion thkkness guage
12Cost of replaceable partsHighLow
13Probaility of replacement of replacable parts1 in a year1 in more than 5 years
14Failures that stops the process1) Probe
2) Battery/Power source
3) Couplant
4) Device failure
1) Device failure (Computer failure)
15Storage limit9986 values onlyNo such IIimits
16Computer dependency No dependency for detection operationAlways needed
17Cause of Error in detection1) I..ack ofcouplant
2) Probe not calibrated
3) Probe failure
4) Device failure
5) Component thickness
greater than limit
6) Error in thickness
measurement 7) surface irregularities (not flat) at the point
of detection 8) Probe not placed at the
predefined location
1) Different profile component
2) component not struck at
the predefined location
18Process control to prevent errorsCnmplex - Need many checks - automation requires adding mechanisms for each cause of errorSimple - Adding a camera can address the issue
19Operation redundancy on failureNo redundancy - need to wait for replacement - Process stopped1) Has redundant sonic sensor
2) Having another computer as a backup can continue the peration
20Post process reportTo be created manuallyGenerated test report automatically
21Device failure due to improper usage1) Couplant not applied as desired
2) Mishandling of probe
22Detection error - Ductile detected as GrayPossiblePossible
23Detection error - Gray detected as DuctilePossibleNot Possible
24Skill level desiredHighLow
25Decision makingManualAutomated
User Interface ScreenSystem Evaluation