FAQ

Magneto inductive rope testing in general

SMRT stands for „Stuttgart Magnetic Rope Testing“. In common parlance, magnetic induction rope testing is also referred to as “MI testing”.

Wire ropes in operation have a limited service life. Safe operation is therefore only possible if the ropes are inspected regularly and discard maturity, i.e. the rope condition at which the rope must be replaced, is detected safely and in good time before a dangerous operating condition occurs. Usually ropes indicate their incipient destruction after a certain running time through abrasion and wire breaks. Wire ropes distribute their stress over up to four hundred individual wires and are usually still safe to operate even if some of the wires have broken. The discard wire breakage numbers are specified in the respective standards according to the rope application. Only the outer wires of a wire rope can be inspected visually. The inner wires remain hidden from visual inspection. The illustration shows the cross-section of a fully locked suspension rope. Visually, only the outer Z-position can be assessed.

For safety-critical applications, it is therefore necessary to measure the outer and inner condition of the wire rope. For this purpose, the magnetic induction method became established very early on because of its practicality and reliability. In particular, operators of cableways and haulage ropes in mining use the magnetic induction testing of wire ropes.

The history of magnetic induction rope testing goes back to the beginning of the 20th century. In 1906, the South Africans McCann and Colson described the magnetic testing of wire ropes for the first time. In 1931, research work in the field of magnetic induction rope testing was started by Woernle at the Institute for Materials Handling Technology at the University of Stuttgart (IFT). Until the seventies, the magnetisation of the rope was carried out by means of coils with direct current flowing through them. In an effort to further simplify magnetic-inductive rope testing, a testing device with permanent magnets was developed in the mid-1970s by the Institute for Conveying Technology at the University of Stuttgart. By using high-performance magnetic materials, the weight and dimensions of the magnetisation unit could be reduced considerably.

In principle, magnetic induction rope testing can be used to test all types of steel wire ropes.

Yes, EN 12927:2019 requires a magnetization by the test equipment in the core of the rope of at least 1.9 Tesa.

Yes, wire breaks mean a change in the metallic cross-section of the rope. Even the smallest changes are reliably detected. Rope testing equipment MESOMATIC

Rope tester SMRT

More than 80 years of research and experience of the Institute for Materials Handling and Logistics IFT of the University of Stuttgart have gone into the development and continuous improvement of the SMRT devices.

MESOMATIC is a development partner of the Institute for Mechanical Handling and Logistics IFT of the University of Stuttgart, produces the SMRT devices and is responsible for worldwide sales and service.

In addition to reliable operation, special emphasis is placed on easy handling under the sometimes difficult conditions of practical use.

The SMRT devices are designed for one-man operation, act independently of weather, surface and light conditions and are not affected by snow, ice, dirt or poor lighting conditions. The design of the magnets and the measuring coils ensures that even the smallest and most varied faults on and in the rope can be reliably detected, displayed and thus interpreted.

  • 24/7 use

  • Harsh environmental conditions

  • Precise analysis

  • Permanent surveillance

  • and much more.

The SMRT units are available in 4 standard sizes

  • SMRT 25 for rope diameter 5..28 mm

  • SMRT 40 for rope diameter 14..45 mm

  • SMRT 60 for rope diameter 35..62 mm

  • SMRT 70 for rope diameter 35..70 mm

Rope diameters up to 140 mm can be tested with special designs

The following minimum equipment is required for a magnetic induction rope test:

  • 1 rope tester SMRT (24 / 40 / 60 / 70)

  • 1 measuring box

  • 1 pair of measuring coils (size depending on rope diameter)

  • 2 pairs of guide blocks (size depending on rope diameter)

  • 1 measuring wheel

  • 1 laptop for operation, display and evaluation

Yes, there is the SMRT 1.5 upgrade kit that allows you to upgrade your existing equipment to the most modern level. You can use all the advantages of the new SMRT 1.5 measuring control with our upgrade package and continue to use all your hardware (magnet, measuring coils, guide jaws) unchanged.

In addition to the possibility of wireless measurement (WLAN), the new generation offers forward and backward movement during measurement and the use of the new SMAQS Recorder software. You can find all the advantages for download here.

With the new SMRT 1.5 system, the SMRT series has been brought up to the latest state of the art. In addition to the possibility of wireless measurement (WLAN), the new generation offers forward and backward movement during measurement and the use of the new SMAQS Recorder software. You can find all the advantages for download here.

If space is an issue, the measuring box can also be placed next to the magnet.

The SMRT units can be used both mobile and stationary.

The laptop is transported in a sturdy transport case with an integrated charging tray for the batteries of the measuring electronics and space for the measuring electronics and other accessories.

The scope of delivery includes 2 batteries (one battery as a spare)

No, one measuring electronics can be used for several magnets.

  L W H Weight
  [mm] [mm] [mm] [kg]
SMRT 25 260 105 150 6,8
SMRT 40 380 145 170 13,0
SMRT 60 460 216 285 26,0
SMRT 70 500 216 280 30,0
Measuring box 200 120 95 1,0
Measuring case 525 435 216 15,8
SMRT 25 in Pelicase
with coils and guide jaws
471 357 175 11
SMRT 40 in Pelicase
with coils and guide jaws
525 435 216 25
SMRT 60 in Zargesbox
with coils and guide jaws
600 400 410 48
SMRT 70 in Zargesbox
with coils and guide jaws
600 400 410 52

3

The rope testers are transported in a sturdy transport case with an adapted inlay together with the measuring coils and guide jaws.

The measuring coils and guiding blocks are interchangeable so that the rope tester can be centered optimally on the rope and the measuring coils can be positioned as close as possible to the rope.

The rope testers are certified according to EN 12927:2019 by the IFT (Institute of Mechanical Handling and Logistics) of the University of Stuttgart. According to EN 12927:2019, recertification is required every 3 years, which we are happy to perform for you.

The SMRT 1.5 measuring electronics and the measuring coils as well as the closed measuring case comply with protection class IP 64. The magnetic head can be cleaned with a high-pressure cleaner after dismantling the coils.

After removing the measuring coils (possible without tools!), the tester is completely without electronics and can be cleaned (even with a high-pressure cleaner!) without any problems.

Yes, this is possible in principle, but it is more difficult to answer support requests because we then have no knowledge of the laptop’s condition and system settings.

Yes, there are no license costs, because the software may be used on multiple computers.

Yes, we offer a pneumatic lifting device for the SMRT 60 and the SMRT 70, which enables manually controlled automatic opening and lifting of the rope tester.

Yes, a so-called drawbar is included in the scope of delivery. However, this is only universal within certain limits. The connection to the drive/ice scraper must always be adjusted on site. This drawbar is a bolted tool in H-shape. Two perforated plates on the sides and a centre section for stiffening. We can gladly provide you with the drawings.

The compressed air cylinder is a cfk cylinder (composite material) with a volume of 6.8 litres and 300 bar. The big advantage of the cylinder is the significantly lower weight compared to a steel cylinder. The use of cfk cylinders has proven itself for many years.

This cannot be said in general terms, depending on the rope diameter (due to the increased magnetic force as there is more metallic cross-section). On average, it can be assumed that 50-60 actuations (1 actuation = 1 x up + 1x down) are possible with one bottle filling.

Depending on the self-sufficiency requirements of the rope test, it may be advantageous to have a second cylinder. However, the cylinders are equipped with a pressure gauge so that the operator can estimate how much compressed air is still available. In addition, the compressed air cylinder can usually be filled in any diving shop or at the fire brigade.

Come to us with your requirement. We will be very happy to check how we can meet your special requirement.

We usually have all necessary spare and wear parts in stock or can manufacture them at short notice. The University of Stuttgart and MESOMATIC both have a long history, which guarantees continuity and ensures the long-term availability of spare parts.

We have the option of doing an online demonstration, or you can come to us at the impressive rope lab at the Institute of Mechanical Handling and Logistics at the University of Stuttgart, or we can come to you and demonstrate the equipment at your facility or your customer’s facility.

Rope testing with SMRT

The connection between the laptop and the rope tester is established via WLAN. Alternatively, in poor ambient conditions (e.g. a lot of steel in the surrounding area), a cable connection can also be used.

On an open track with a clear view, a range of 80 -100 m is possible.

Once the measurement is started, a loss of connection will not result in any loss of data. Disconnecting the connection can take a long time without any problems, the measurement data is completely written to the internal SD card. After successful completion of the measurement, the complete measurement data can be loaded from the SD card.

At least 20 hours can be measured with one battery charge, even at low temperatures.

Measurements can be performed in the velocity range 0.3 to 5 m/s.

The EN 12927 standard states that one measuring point should be recorded for every 1 mm along the length of the rope (example: if the rope is running at 2 m/s, frequency setting to 2000 Hz). With our system, the frequency is adjusted automatically. The measuring wheel serves as a trigger. This means that one measured value per 1 mm is stored. Completely independent of the speed. When the measuring wheel moves 1 mm, a measured value is written.

Corrosion produces a clear widening of the measurement signal in the MI measurement record. It can therefore be recognised. However, it cannot be said across the board that every signal widening in the MI measurement record is also due to corrosion. This means that a signal widening cannot be equated with internal corrosion. In this case, the corresponding rope zone (in which the signal widening occurred) must be visually inspected. This is the only way to draw concrete conclusions between the MI measurement and corrosion. Translated with www.DeepL.com/Translator (free version)

Our team will be happy to support you in selecting the appropriate equipment and, of course, also through training in building up your rope testing know-how.

We recommend training to familiarise our customers with the operation of the measuring programmes and the handling of the magnetic head and, if necessary, the lifting device. This can be carried out on your premises or at the IFT of the University of Stuttgart, taking into account the valid COVID-19 regulations.
One training day is usually sufficient to be able to adequately assess ropes. If the training participants already have previous knowledge in handling magnetic heads, the training can also be carried out online in half a day.

Do you still have questions that we have not been able to answer here?

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