Services - SPM

1965 - The history of SPM began in the 1960s. At that time, condition monitoring consisted of putting an ear to a wooden rod or screwdriver and listening to the sound of the machine.

If something could be heard, it was usually already too late. A.P. Møller, the Danish shipowner, found out from bitter experience that the cargo pumps of his tankers were breaking down far too often without forewarning. An inventor and an enterprising financier decided to do something about it.

1969 - Eivind Søhoel, the inventor, patented the shock pulse method which identifies the weak shock pulses from rolling element bearings.

1970 - The SPM company was formed. After only a couple of years, we developed the first rules for evaluating the measurement signals that Søhoel succeeded in isolating. Even today, we are devoting major resources to developing these rules, both in the laboratory environment and on the industrial scene.

1980 - SPM has installed millions of measurement points, and has sold 40 000 units of the portable 43A measuring instrument - a true classic.

1984 - After intensive work, we were able to incorporate, in the deepest sense of the word, the lubricating condition of the bearing into the SPM method.

The second half of the 1980s saw a virtually revolutionary development of the software. Our world and that of our customers became computerized.

1990 - Shock pulse measurements and vibration measurements were combined in a first step towards comprehensive condition monitoring. At the same time, SPM developed life cycle analyses for an overall assessment of the economic consequences of condition monitoring.

1997 - EVAM is introduced, confirming the steady efforts of SPM to develop simpler and more efficient evaluation methods.

Worldwide Capability
SPM Instrument is a dynamic corporate network of international scope. A purposeful expansion has resulted in our worldwide capabilities of today:

Research and development programs continuously ongoing at our R & D department in our facilities in Strängnäs.

Factories in Sweden and India enabling the total production of all SPM products.

Customer training programs available in most industrialized countries.

Sales and service companies in Austria, Benelux, Finland, India, Italy, Norway, Singapore, Sweden, South Africa, United Kingdom and USA.

Qualified and carefully selected representatives in most other industrialized countries.

Technical staff experienced in applying the skills needed to reach practical solutions through development programs for each individual customer.

The headquarters of the SPM group are situated in Strängnäs, Sweden where also the R & D, the main part of the manufacturing and sales support takes place. Here is also the base of the Swedish sales organization. The SPM Group employs about 140 persons of which about 60 at the facilities in Strängnäs

The Swedish plant has a fully equipped factory and produce the full product range. The plant in India produces a limited range of the products for the Indian domestic market. The quality system at SPM is approved according to ISO 9001 and the environmental system in accordance with ISO 14001 is on the way.

Research and Development
Technical innovation is a continuous goal at SPM. Our laboratories are well equipped for trials, examinations and verifications of R & D tasks within electronics as well as mechanics to refine our technique and improve our products.

Marketing and Sales

Our Marketing Department is responsible for all international sales support including technical and promotional material, training and information. The Swedish sales department takes care of the direct sales to the Swedish market.

The Training Center, situated in connection to the headquarters, provides regular standard courses as well as customer adapted training courses for adequate handling of all SPM hardware and software.

The international sales organization is also using these facilities for training the personnel. The Center is suited for lectures, hands-on demonstrations and a suitable place for the consultation of SPM specialists

SPM's Installation Service is very well suited to efficiently install the SPM maintenance systems and equipment. On sites, where a customer wants to use his own personnel for the installation work, SPM can assist with supervisors.

Controlled Maintenance Programs
SPM has the expertise to develop maintenance programs. We can supply proposals in detail, make installations and implement software packages that form cost-efficient and flexible monitoring and maintenance programs for our customers.

Special Applications
SPM assists other companies with the design and development of special applications of our technique or products manufactured on an OEM basis.

We are making assumptions, based on over 30 years of experience with machine condition monitoring:

Point 1: You do not want to know about machine condition, as long as it is good. 
Point 2: If something starts to go wrong, you want to know in advance and in detail. 
Point 3: It must be cost efficient.

Considering that a good condition monitoring system pays for itself within a very short time, we offer an appropriate technical solution:

To save your time and clearly indicate the maintenance priorities, our instruments automatically evaluate measured data and supply a green - yellow - red condition signal as first hand information. This is backed up with comprehensive computer software (for the cases where you need all the details).

You have the choice of the leading condition monitoring methods, including vibration analysis, all in one instrument. For each application, you can select the most cost-effective method which meets the technical requirements.

Considering that you have to pay, in time and effort, for each bit of information on each measuring point, you will find this approach economically attractive as well as technically sound.

What do you need to know?

Use the optimal tool for each target

The concept of strategic condition monitoring is quite simple. The types of mechanical faults which can occur on a given machine are well known to your maintenance personnel. What they need is, first: a straightforward message that a fault is developing, and second: an indication of its severity. What they do not need is a flood of barely comprehensible (and expensive) data.

There is no single method which can measure everything at a reasonable price. However, if you define the target (the expected machine fault, which you must do in any case), you can easily pick the monitoring method which will provide the fastest, cheapest, and most reliable result.

Shock pulse measurement (SPM® Method)

The primary targets are rolling bearings (damage and lubrication condition).
In many applications, these are the only machine elements which need monitoring. The method also reacts to shaft misalignment, cavitation, and other faults. It requires little input data and is fast and easy to apply.

Vibration severity measurement

Very efficient for detecting the most common machine faults, such as imbalance, structural weakness, loose parts. Little input data needed, easy to apply.

Vibration spectrum measurement (EVAM® Method)

Requires considerably more input to make sense of the data but, used in connection with our comprehensive analysing software, allows you to target difficult problems where other methods cannot give accurate answers.

With industrial condition monitoring, a main cost factor lies in extracting sensible condition information from raw data. Automatic condition evaluation is an integral part of SPM instruments. Based on extensive empirical data, international standards, and machine statistics, they display an easy to understand colour code intended to highlight potential trouble spots. By calibrating and adjusting limit values, you can tune the automatic process with great precision and get an immediate, reliable diagnosis.

World Leader in Machine Conditioning Monitoring

Since 1970, SPM® has been providing the most accurate and detailed machine machine condition information. Starting with the SPM® Method for bearings and now progressing to EVAM® for vibration analysis, SPM® has dedicated its objectives to clearly identify the maintenance priorities. Our instruments and systems automatically evaluate measured data and supply a GREEN - YELLOW - RED condition code as first hand information. The concept of Strategic Condition Monitoring is quite simple. Choose the tool that addresses the mechanical faults that apply to your equipment and choose a cost-effective method that your staff can manage today, and in the future.

SPM® Method + EVAM® Method = "True" Condition Monitoring

The SPM® Method is a proven method for identifying damage and lubrication condition of bearings. Direct evaluation of bearing condtion does not force the user to develop their own database or trend. Now with EVAM®, Evaluated Vibration Analysis Method, other mechanical components are automatically evaluated. Monitoring gears, imbalance and misalignment does not have to involve interpreting a complex vibration spectrum. As with the SPM® Method, the EVAM® Method utilizes a simple, direct, accurate GREEN -YELLOW - RED condition code. SPM Instrument has a wide variety of portable dataloggers as well as on-line systems to fit your needs. For more information on these lines please visit

To learn more about other SPM® maintenance aids and products contact us.

Shock Pulse Monitoring boosts maintenance

The need to eliminate unscheduled equipment repair time is urgent in order to remain competitive nowadays, explains Dennis Peplow.

An industry consultant and president of Prevent Plus, Inc., a Morton, IL company that specializes in providing full preventive maintenance services, Peplow has clients across a wide range of industries. One thing they have in common is the need for proficient machine condition monitoring. Lately, Peplow has been using a unique predictive/preventive maintenance tool — dubbed Shock Pulse Monitoring (SPM) — to provide clients with capable condition monitoring.

The SPM technology, created by SPM Instrument, is based on the principles of machine condition monitoring, which is the assessment of equipment condition, mostly rotating machines such as pumps and fans. It's a cost effective strategy, since it can be carried on while the machine is in use.

Bearing analysis is one form of machine condition monitoring that has been found to be extremely reliable, because bearing lubrication problems are the cause of 75% of all equipment failures. "At the exact moment when the rolling element and the raceway in a bearing come in contact," says Peplow, "there are still no changes in the surface of the bearings, there is still no deformation." During that extremely brief period, the contact produces material acceleration that propagates in an ultrasonic "shock pulse" wave. The magnitude of those waves depends on the condition of the surface, and the peripheral velocity of the bearing. Picking up those early-stage signals that tell exactly how bearings are doing is the foundation of SPM.

Shock wave signals, however, are very weak and easily get lost amidst other vibration signals; the damage to the bearing has to reach a severe stage before it gets noticed by traditional vibration analysis. Focusing exclusively on "immediate contact waves" by means of an especially tuned transducer allows SPM technology users to predict bearing performance and prevent equipment damage earlier, and more accurately.

Peplow finds that all his customers' have the same concerns — they cannot afford unscheduled downtime. Scheduling repairs to fit within the department's workload and timetables, instead of having to take a piece of equipment off-line to work on it, or even worse, to replace it, is a benefit of the lead-time provided by exact bearing condition information. "Pinpointing the trouble with exactness is clearly the biggest strength of vibration analysis," says Peplow. "SPM gives me time to act before trouble becomes unmanageable."

As an example, Peplow recalls the case where a customer had an exhaust blower assembly that was functioning so poorly that its life expectancy was barely between 4 to 6 weeks, causing numerous production bottlenecks. "The worst part was that they never knew when it was going to quit on them," explains Peplow. Downtime was typically 6 to 8 hrs. because of secondary shaft damage, and downtime costs reached to $3,000 to $4,000 per hour.

Additional lubrication and balancing were tried, and they didn't make a difference on the readings. "SPM allowed us to verify that there was a bearing design problem, not merely a case of lack of lubrication or poor balance," says Peplow. A different bearing design and type was the final solution. "After the design weakness was corrected, we were able to confirm through the readings that the change has been successful."

Helping maintenance staff switch from a "wait until it fails" attitude to a predictive/preventive mode is often an assignment for Peplow and his team. "Here is where I find SPM particularly good," he says. "It's easy to learn and simple to use so it doesn't end up locked in a cabinet because it's too valuable, and because no one wants to use it anyway." Readings on SPM monitoring equipment are provided by means of a simple color code — green for safe, yellow for warning, red for stop.

"SPM tells us exactly what we need to know," remarks Peplow. It doesn't bury you with irrelevant data."

Even if bearings are in good condition, knowing that for sure will avoid scheduled, but unnecessary maintenance. "We can save our customers money by reducing catastrophic failure, as well as by avoiding unnecessary repairs," explains Peplow. "In both scenarios, the result is increased uptime and that means, of course, increased production."

Key Benefits

  • Most accurate Instrument
  • Detailed machine condition
  • SPM® Method + EVAM® Method = "True" Condition Monitoring
  • Direct evaluation
  • Simple Colour Code - Easy to use


SPM is an abbreviation for the Shock Pulse Method, which is a patented technique for using signals from rotating rolling bearings as the basis for efficient condition monitoring of machines. From the innovation of the method in 1969 it has now been further developed and broadened and is now a worldwide accepted philosophy for condition monitoring of rolling bearings and machine maintenance.

Difference between shock pulse and vibration

Consider that you have a metal ball that hits a metal bar. At the moment of impact, a pressure wave spreads through the material of both bodies (1). The wave is transient (quickly dampens out). When the wave front hits the shock pulse transducer, it will cause a dampened oscillation of the transducer's reference mass. The peak amplitude is a function of the impact velocity (v).

During the next phase of the collision, both bodies start to vibrate (2). The frequency of this vibration is a function of the mass and the shape of the colliding bodies.

Processing shock pulse signals

A shock pulse transducer reacts with a large amplitude oscillation to the weak shock pulses, because it is excited at its resonance frequency of 32 kHz. Machine vibration, of a much lower frequency, is filtered out.

The first frame shows the symbol for a transducer and, below, the vibration signal from the machine, with superimposed transients at the resonance frequency, caused by shock pulses.

The second frame shows the electric filter which passes a train of transients at 32 kHz. Their amplitudes depend on the energy of the shock pulses.

The transients are converted into analogue electric pulses. The last frame shows the converted shock pulse signal from the bearing, now consisting of a rapid sequence of stronger and weaker electric pulses.

Shock pulse patterns

The filtered transducer signal reflects the pressure variation in the rolling interface of the bearing.

When the oil film in the bearing is thick, the shock pulse level is low, without distinctive peaks.

The level increases when the oil film is reduced, but there are still no distinctive peaks.

Damage causes strong pulses at irregular intervals.

Measuring Operating Condition

The Shock Pulse meters measure the shock signal on a decibel scale, at two levels.

A micro processor evaluates the signal. It needs input data defining the bearing type (ISO number) and the rolling velocity (RPM and bearing diameter).

Surface damages in a bearings causes a large increase in shock pulse strength, combined with a marked change in the characteristics between stronger and weaker pulses. Shock values are thus immediately translated into measurements of relative oil film thickness or surface damage, whichever applies.

Vibration Severity

The vibration severity measurement is a very efficient monitoring method for detecting such common machine faults as imbalance, structural weakness, loose parts etc. Few input data are needed and it is easy to apply. The evaluation is based on international industrial standard. ISO 10816. The measurement returns the RMS value of vibration velocity in mm/s or inch/s

The majority of industrial machinery belongs to the vibration classes 2, 3, and 4:

Class 2: Medium size machines without special foundation
Class 3: Large machines on rigid foundations 
Class 4: Large machines on soft foundations.

For example, most smaller process pumps in a chemical plant would be in Class 2. A 100 kW fan on a concrete foundation would be in Class 3. However, the same fan fastened to the less rigid deck of a ship could be considered as Class 4.

Class 1 refers to independent parts of machines, for example electric motors up to 15 kW. Classes 5 and 6 are used for heavy reciprocating prime movers and machines which are intended to vibrate, such as vibrating screens.

On the instrument and on the SPM software Condmaster screen, the ISO values for good and acceptable are shown in green, just tolerable is yellow and unacceptable is red. Easy to read and understand.

The Evam Method

EVAM® is SPM's newest method for machine condition monitoring in industrial environments. The letters stand for Evaluated Vibration Analysis Method.

EVAM combines a number of established vibration analysis techniques with a machine specific statistical evaluation to supply easy to understand machine condition data. The method has been developed to allow large scale, cost-efficient condition monitoring of industrial machinery:

  • fast menu-guided setup of measuring points
  • easy data collection with hand-held dataloggers or on-line equipment
  • automatic condition evaluation.

EVAM fills the gap between broadband vibration severity measurements (the ISO recommended method) and the traditional type of spectrum analysis requiring a high level of operator training. Used at the most basic level, EVAM supplies much more data than the ISO method without demanding more skill and time. Moreover, spectrum analysis is an integrated part of the software, allowing the direct monitoring of a large number of specific mechanical faults.

EVAM works in three stages:

1. Vibration time record analysis

This automatic data processing returns up to 9 parameters for rotational forces, shock forces, and friction, providing a detailed picture of the vibration forces active on the machine.

2. Vibration spectrum analysis

EVAM uses FFT to calculate one or several spectra per measuring assignment. For each measuring assignment, the user can select specific machine faults (unbalance, misalignment, motor and gear box faults, bearing damage, etc.) from a pre-programmed list of fault symptoms. 
This relieves of time-consuming task of searching the spectra for relevant condition information. Fault symptoms are automatically highlighted in the spectrum, and an individual parameter value is returned for each of them. This allows trending on specific machine faults, or a direct evaluation made by the software:

3. Machine specific condition evaluation

Using a set of vibration readings obtained during normal machine operation as base line data, all monitored parameters are compared with their mean values and standard deviation and displayed as condition values against a GREEN - YELLOW - RED scale. Without having to study any details, the user is provided instantly with a detailed status report covering all his selected condition and machine fault parameters. 
EVAM is used in hand-held data loggers, along SPM bearing monitoring, ISO vibration severity monitoring, and other measuring and recording functions. SPM also supplies an on-line unit for frequency ranges up to 10000 Hz.

The software is Condmaster®Pro, a Windows 95/NT version of the SPM Condmaster, with the EVAM functions and a graphical overview of machine status as the main new features.


Round the clock - stand alone surveillance
Continuous monitoring, 1 to 4 channels. True RMS machine vibration. True SPM bearing condition.
Green - Yellow - Red status display, 5 programmable alarm relays, 4 - 20 mA analog output on all channels.

Guard your assets - it pays!
Machine GuardTM MG-4 is the ideal early warning system and emergency shutdown for unmanned machine units. You can select power supply, measuring ranges, alarm delays and much more. Easy to program, no operating costs.

They grow on you: Basic - Logger - Expert

Tester T30 and Analyser A30 are now available in three versions. 
Measures true SPM bearing condition, true vibration severity, temperature and rotational speed. Manual recording of measuring results. An economical way of monitoring machine condition.

The same measuring functions, but with the powerful support of the SPM software Condmaster®Pro. Download measuring rounds with complete data, comments and checkpoints to the instrument, upload results to the PC. The fastest and cheapest way to monitor a large number of measuring points with a hand-held instrument.

A data logger with the added functions for vibration spectrum and symptom analysis, based on SPM's unique EVAM® method. Logger and Expert also allow simultaneous long-time recording of shock pulses, vibration severity and either speed or temperature.

You can easily upgrade, at any time.

New Condition Monitoring Modules

CMM System - a wider range of modules available.

Small modules provides maximum flexibility.
The CMM System has grown to a more flexible program of modules, with more functions and improved performance. The modules measures true SPM bearing condition, true vibration severity and temperature. They can be equipped with a status display for measured values and evaluated machine condition in green-yellow-red.

The signal from 4-20 mA analog is universally used in PLC systems or other computerized monitoring and control systems. You simply tap existing signal cables to get a read-out, an alarm display, or a relay connection wherever you require them.


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