Calculators, Simulations & Severity Charts

This program allows you to calculate bearing defect frequencies and then view them in a spectrum. Simply enter the number of balls, ball diameter, pitch diameter and contact angle and press “calculate.” The bearing defect frequency calculator will then give you options for which defect frequencies to display in the spectrum. See ball spin frequency, inner race, outer race, harmonics and sidebands. Play around with the numbers and see how they effect the bearing defect frequencies and the patterns in the spectrum.

What is the relationship between the Fmax or frequency range you select on your data collector, the number of lines of resolution, the time waveform length, the number of samples and the number of shaft rotations the test will capture? This little calculator will help you learn about these relationships or it will help to remind you if you forget.

If you want to analyze a gearbox in the time waveform and wish to configure your analyzer to collect three revolutions of the shaft, this calculator will help you determine what Fmax to use and how many lines of resolution you will need.

This program will calculate the shaft speeds, the gearmesh frequencies, and the Gear Assembly Phase Frequencies [GAPF] (from common factors) and the Hunting Tooth Frequency [HTF]. The utility will also simulate a spectrum with the shaft frequencies and gearmesh frequencies.

This simulator will let you play with characteristics of an A.C. induction motor. What is the relationship to the number of poles, the actual running speed and the slip frequency? How do these characteristics appear in the spectrum when the motor has a problem? How about motor rotor bars? Where do these appear in the spectrum and what patterns do they create?

What is the relationship between the number of pump impeller and diffuser vanes and the vibration produced by the pump? What is the relationship between the number of fan blades or compressor vanes and their relationship to fan and compressor vibration? This simple Flash® simulator will allow you to explore these questions and answers on your own.  Enter a run speed, number of vanes (blades etc.), number of diffuser vanes and then press “Calculate.” You can check the boxes next to “Show harmonics” and “Show sidebands” to see the effect this has on the spectrum at the bottom. Use the Fmax slider bar to change the frequency range of the plot at the bottom to display the information of interest.

This powerful units conversion calculator allows you to convert all sorts of data units.

This easy to use program allows you to convert vibration units from acceleration to velocity to displacement in both imperial and metric units, in/s, IPS, mm/s, g, rms, pk, pk – pk.

Why might a piece of equipment fail?  Can we put a ‘force-field’ around the machine to eliminate all possible sources of defects?  We use acceptance testing to protect our machine from outside defect sources.  This can help to eliminate issues from cheap spares, poor transportation and unqualified service providers doing work that does not meet our requirements.  We also need to protect our machine from ourselves!  We use condition monitoring to ensure our installation, operation and maintenance practices prevent defects.  Our machine will then have the best chance of delivering the maximum value to us.

Maintenance can be constantly reacting to problems that arise.  These problems can be because Procurement purchase the cheapest option or the equipment is not operated in the optimal way.  We can use condition monitoring to give us an early warning of these problems, and Maintenance can then be prepared and proactive.  If Procurement purchase the best and most suitable equipment, Operations take care of the equipment etc,  we will get the maximum value from the equipment and reduce the total cost of ownership.  Everyone is responsible for reliability, from the design phase through to operation.

• We can reduce our business costs if we focus on reliability improvement.  If we focus on reducing our maintenance costs then our reliability will worsen.  But if we focus on improving reliability then our maintenance costs will go down as a result.

A defect is initiated and the condition of our machine begins to degrade.  The good news is that the machine gives us warnings, eg high-frequency sound, temperature change, vibration etc, and we can use condition monitoring to detect these.  With advance warning we can schedule the repair and order spares.  If we don’t detect or deal with the problem then the cost goes up and the risk to our equipment and business goes up.

Reliability will improve over time, but it can be hindered by factors such as budget cuts or the departure of the reliability team leader, which then leads to a decline in reliability. In response to the resulting issues, there may be renewed focus on improving reliability, with the reliability program being reinitiated to bring about improvement. However, if a culture of reliability has not been established, this cycle of improvement and decline may persist, particularly if there are additional cost-cutting measures or layoffs. It is important to maintain an unwavering focus on reliability to prevent this type of rollercoaster effect.

The optics of your infrared camera focus the infrared radiation from the target object onto the detector. With a 320×240 array in your camera detector you will have 76,800 individual elements capable of detecting and measuring thermal radiation.

As current moves through resistance, heat is generated. If we double the resistance, we double the amount of heat generated because that relationship is linear. However, if we double the current, the heat will increase by a factor of four because that relationship is exponential. If we want more heat from our hotplate we turn the dial to increase the amount of current passing through the heating element.

What we view through our camera is the ‘field of view’. With a high-resolution camera, each pixel in that field of view (the ‘instantaneous field of view’) covers a smaller area of the image. Higher resolution gives greater detail which in turn gives us a better ability to detect and measure temperature.

Moving left and right can identify and then help to avoid reflections. If moving does not help, the source of the reflection can be blocked. A simple sheet of cardboard can be enough to act as a barrier.

‘Span’ is the range of temperatures we are using within the overall range of our camera. ‘Level’ is the mid-point of our span. A narrow span will give more contrast between different temperatures, ie each colour in our chosen palette will represent a smaller unit of temperature.  The level and span that you set should include what you want to measure or you risk missing important detail.

An arc – the flow of electricity through the air – can be very violent.  An arc involves very intense light and heat, a rapid expansion of air, molten metal and shrapnel, sound and pressure waves, and gasses.

The amplitude of our measurement will change depending on the distance to the target and the angle.  Ultrasound is very directional so we can use this to help pinpoint the source of the signal.  Move around the target to find the angle and distance that gives the highest amplitude.

The further away from the source of a sound, the lower the amplitude is.  An amplitude of 100dB, 1m from the source will drop by 6dB at double the distance from the source (2m).  Double the distance again and the amplitude will drop another 6dB.  Consider the Inverse Distance Law when performing tests.  Measurements should be taken from the same distance each time to ensure repeatability.

Ultrasound frequencies are, by definition, above human hearing range.  We want to take the sound we want to hear and translate it into a sound we can hear.  A mixer frequency is added and the heterodyning process then uses the sum and difference of the mixer and ultrasound frequencies to bring us an audible signal (the difference) and a very high frequency (the sum) that we don’t use.  What we hear is “the same” – a ‘click’ (at ultrasound frequency) with a one second period will be heard as a one second ‘click’.

An airborne sensor with a listening angle of 30 degrees will have a listening circle with a diameter 1.15 times the distance from the target.  If we are further from the target we would be testing a larger area which will be less precise.  We should also consider the effect of the Inverse Distance Law.  If we imagine shining a flashlight on a target and moving closer or further away, we would see the illuminated area grow and shrink

Adjust the speed and amplitude of vibration in this animated fan and see how these two varibales effect the time waveform. As you increase the speed, the wavelength of the sine wave decreases. As you increase the amplitude, the height of the sine wave increases. This simulator will help you to understand the relationship between the movement of the fan and the vibration produced by its movement.

We have a new single-plane vector balance program. Simply click and drag on the “original” vector and the “trial run” vector and you can see where the correction weight should be placed. You can move the location of the trial weight and change its mass. You can even set your phase convention (with rotation or against rotation (normal)) and you can add fan blades to see how the mass should be split between them. The original version of this program was purchased from Steven Young.

In this simulator you can adjust the speed, amplitude and relative phase between two fans. This will help you visualize and understand the concept of phase. Simply adjust the knobs or type in values in the fields.

In this simulator you can see that as the mass moves around with the shaft, it creates a vibration. We can understand this vibration or quantify it in three different ways. We can talk about how far the shaft moves up or down or side to side under the influence of the mass(displacement). We can talk about fast it is moving (velocity) or we can talk about how fast it is speeding up or slowing down (acceleration).

This signal generator will help you understand how the waveform relates to the spectrum. You can add two or more signals together and see the resultant spectrum. You can also play with amplitude and frequency modulation as well as see how different windows affect the signal.

ISO 10816 Displacement – interactive vibration severity chart. This chart provides vibration alarm limits as per ISO standards in units of displacement. Click on the units button on the bottom right of the chart to toggle between imperial and metric units.

ISO 10816 Velocity – interactive vibration severity chart. This interactive ISO vibration severity chart provides vibration limits in units of velocity for typical machines. Press the “unit” button at the bottom right of the graph to toggle betwee metric and imperial units.

Use this ISO 1925 chart to determine appropriate acceptable vibration levels and criteria for your dynamic balancing projects.