Math formulas

DEWESoft 7 offers all major arithmetic, logic, algebra and measure functions which can be combined with any measured of calculated channel to create sophisticated formulas. Math formulas in DEWESoft 7 included following functions:

• Basic operators: plus, minus, multipy, divide, div, mod and power
• Functions: square, square root, absolute, truncate, random, logarithm (base2), logarithm (base10), natural logarithm, exponent, if condition, min, max
• Trigonometry: sin, cos, tan, asin, acos, atan, Pi
• Logic: less then, equal, more then, less then or equal, more then or equal, not equal, not, and, or, xor
• Signals: number of samples acquired, sample rate, time elapsed, sine wave, square wave, triangular wave, noise
• Measure: pulse width, stopwatch,
• Events: key press events

Filters

DEWESoft 7 has many different types of filters grouped into three filter modules:

• IIR filter
• FIR filter
• FFR filter

Classical electrical filters like Chebyshev, Butterworth and Bessel can be made using IIR filter module. These filters allow also single and double differentiation and integration.

FIR filters are even smarter. When signals are filtered, filter introduces a phase shift, so the output is delayed compared with input. DEWESoft FIR filter filters data without any phase shift or delay, so it is perfect for analysis of signals which doesn't allow having phase shifting or delaying.

FFT filter performs an FFT calculation and cuts a certain range of signal to create sharpest possible filtering.

Statistical calculation

DEWESoft 7 offers several statistical calculation grouped into following modules:

• Basic statistics
• Array statistics
• Latch math
• Classification
• Counting

Statistic like average, RMS, QRMS, Minimum, Maximum, Crest, Peak, Peak-Peak, Variance and standard deviation can be calculated in specific time intervals, as a single value or based on events.

Reference curve

For comparing the data with predicted curve or with previously measured data DEWESoft 7 offers modules to create time, FFT or x-y based reference curves and use that as a limit criteria. There are four types of reference curves in DEWESoft 7:

• Reference curve: time based, single value based, dual value based
• XY reference curve
• FFT reference curve
• Constant

Exact frequency

This quite smart module can calculate frequency from a sine wave with precision of 1 mHz even if the input sampling rate is not very high.

Power module

Power module is very extensive module which can calculate power and power quality parameters from measurement of voltage and current.

It has software PLL which measures the base frequency down to 1 mHz resolution. The line frequency can be 50, 60, 400, 800 and also variable. In fact, DEWESoft power module is, as we hear from our customers, the only PC based software which can measure correctly variable frequency sources, like frequency inverters.

DEWESoft calculates single or three phase power with or without current channels. It calculates active, reactive and total power. It also calculates base and higher harmonics of voltage, current, power, and impedances. The background harmonics can be easily subtracted to allow differential measurement to normal operating conditions.

The power module calculates also line unbalance, periods and flicker values according to the power quality standard.

Order tracking

Order tracking is a procedure to transform data, mostly from vibration, to the angle domain based on the frequency of rotation. If we have a rotary machine, lots of excitation forces are related to some harmonic component of rotation (for example unbalance or coupling misalignment). When the frequency of excitation is the same as the natural frequencies of structure, we get resonance effects.

Main features of DEWESoft 7 order trcking module:

• Simple and easy to setup
• Dedicated re-sampling method for sharp order separation
• Measurement in time domain to keep all benefits
• 2D, 3D waterfall in order or frequency domain
• Amplitude, phase extraction
• Recalculation in post processing
• Phase synchronous rpm input with 12.5 ns resolution

DEWESoft 7 order tracking takes time domain data and transforms the data based on frequency of rotation and extract any number of harmonics (amplitude and phase angles) which can be displayed in Bode, Nyquist, 3D FFT, real time x-y and orbit plot. The plane view FFT clearly shows the excitation forces, natural frequencies and all the resonances so it gives a clear picture of the dynamic behavior of the machine.

In addition, the order tracking module is also used to show an orbit plot which is used to observe bearings or movements of rotating machines. The Order tracking module extracts specific harmonics in the orbit view and also averages them.

Torsional vibration

Torsional vobration module calculates the torsion angle and angular vibration measured from two encoders mounted on each side or the shafts. The difference between the rotations of each side is the torsion twist of the measured shaft. Torsional vibration can be an input for order tracking to give clear idea about dynamic behavior of shaft.

Torsion vibrations module main features:

• Time domain measurement
• Angle based view
• Additional to other functions (analog, CAN, GPS, video, ...)
• Configurable displays
• Direct sensor connection
• 80 MHz time base

Several torsional vibration modules can be combined to measure the complicated transmissions.

Combustion analysis

The today vehicle engines can't be developed without the measurements of combustion parameters. The engine speed, pressure inside the cylinder as well as other parameters like needle lift, intake pressures and others are the base for calculating combustion parameters like maximum pressure, position of maximum pressure, pressure derivative, heat release, cylinder temperature, knocking and others.

The RPM data can be acquired from virtually any sensor in the car or a special externally mounted encoder, therefore the same system can be used on the test bed or in the vehicle during normal driving.

DEWESoft 7 combustion analysis module calculates following key features:

• Cylinder pressures,
• Pressure vs. Volume (pV),
• Recorder for CA, time-based, and CAN values,
• MEP values (IMEPn, IMEPg, PMEP) frequency of rotation, cycle count,
• Heat Release (TI, TQ, burn angles),
• Combustion noise,
• Peak-hold and Real-time for any value.

Frequency response function

FRF module is extension software to DEWESoft, which allows to measure transfer functions of mechanical structures with hammer or shaker excitation. The software allows creating or importing geometry of the structure for quick visualization of measurement points.

DEWESoft FRF main features:

• SISO, MISO, MIMO configurations,
• Spectral ODS,
• Geometry editor,
• Mode indicator function MIF,
• Circle fit analyze tool,
• Function generator up to 16 channels,
• FRF from stored timed data,
• Triggered, free-run measure mode,
• Roving hammer excitation support,
• Unv-file export for modal packages (ME-Scope, ...),
• Up to 1000 channels linked over DEWESoft NET,
• Shock response spectrum (SRS).

The chosen natural frequencies can be observed as animation of the structures. Measured data can be exported as UNV files, which is easily imported by the most important analysis packages.

It is also used to define transfer functions of electrical circuits like amplifiers or filters.

Sound level meter

Sound level math section allows calculating typical parameters for sound level measurements from a single microphone. It allows DEWESoft to be used as the typical sound level meter with A, B, C or D weighting. With appropriate hardware (24 bit ADC) it can easily fulfill all the requirements for Class I sound level meter.

Sound module main features:

• Real time narrow band FFT
• 1/1, 1/3, 1/12, 1/24 band octave spectrum
• A-, B-, C-, D-weighting (frequency weighting)
• Fast-, Slow-, Impulse-weighting (time weighting)
• Leq-Calculation
• Sound Level Meter

DEWESoft 7 calculates several parameters online:

Function	Description
Lp (8PL)	Time (F, 8, I) and frequency weighting (A, B, C, ...) sound level (dB)
Lpk	Current maximum sound level (dB)
Weighted raw	Frequency weighted (A, B, C, ...) sound level (dB)
Log	Equivalent sound level (dB)
Lim	Pulse weighted equivalent sound level (dB)
Lpkmax	Absolute maximal sound level (dB)
Lo	Sound exposure [dB]
Lmax, Lmin	Maximum and minimum Lp sound level
LAF50, LAF10, ...	Classes for 0, 1, 1, 5, 10, 50, 90, 95 and 90 dB

Sound power measurement

Sound power measurements are important for noise measurements and qualification of noise emission from machines and products (CE mark). They can be done with two measurement procedures, measuring the sound pessure or the sound intensity. Both are supported with DS MOD DSA system. Following corrections will also be done:

• barometric pressure and temperature (K0),
• background noise (K1),
• surrounding correction (K2),
• measurement aread (Ls).

Human body vibrations

Human vibration is a measurement of effect of vibrations to human body. Especially on work places exposed to vibrations there is a big chance of permanent damage to some parts of human body.

The human vibration module provides measurements to be able to judge the risk of such damage. It is compliant with following standards:

• ISO 2631-1,
• ISO 8041 and
• ISO 2631-5.

Field balancing

DEWESoft 7 provides an easy to use and straight-forward tool for single and dual plane balancing. This add-on is included as an option in every Dewesoft instrument. One or two acceleration sensors and a tacho probe are needed for balancing.

Main features of field balancing module:

• wizard like user interface which guides you through all the steps,
• order tracking based balancing method,
• single or dual plane,
• multiple balancing for two directions saves time (X, Y),
• 2D graph for plane view,
• RPM channel with color indicator (rpm range),
• alarm output if velocity exceeds predefined value,
• displays tacho probe time signal to set trigger,
• vector polar plots of 1st order of all runs (initial, trail, ...),
• weight splitting,
• acceleration, velocity, displacement in recorder,
• time domain measurement.