Transport monitoring with MSR data loggers
The name Kärcher stands for the highest level of cleaning expertise worldwide. Uncompromising quality is the top priority for the internationally operating German family business - also when it comes to shipping products. Kärcher uses MSR data loggers to precisely assess transportation loads.
Kärcher, the world's leading cleaning equipment manufacturer, offers a comprehensive range of products for private households, trade and industry. Headquartered in Winnenden, Germany, the renowned company employs over 10,600 people in 60 countries. They all ensure that customers all over the world receive exactly what they expect from Kärcher: flawless products that meet the highest standards. This high quality standard does not stop at the shipping of the goods.
Determining transport loads in pallet and individual shipping
The MSR data loggers used by Kärcher in this case study were used to monitor the transportation of packages worldwide in order to be able to assess transportation stresses more accurately in the future. A distinction was made between pallet and individual shipping. Various tests were carried out in order to be able to design packaging for individual or pallet shipment:
- Vertical impact test
- Vibration test with variable sinusoidal excitation
In these tests, the packages were subjected to specific mechanical-dynamic loads that simulated the real conditions during transportation and handling. The aim of Kärcher's series of measurements was to evaluate the transport, handling and storage loads on European roads and waterways. The resulting transport loads were then to be compensated for by constructive measures on the packaging and by the use of filling materials.
Various data loggers from different manufacturers were tested by Kärcher for the test application, compared and divided into areas of application. A key requirement for the data loggers was that temperature, humidity and acceleration values should be recorded and stored simultaneously. The MSR145 data logger was selected as it is ideal for long-term measurements thanks to its 900 mAh lithium-polymer battery and additional memory card slot. Another advantage was the small external dimensions of the mini logger.
Which logger for which transportation load?
The required measuring range of a data logger must always be determined depending on the respective measuring task. For example, a relatively small measuring range is usually sufficient for determining acceleration values, such as those that occur during transportation on the loading area of a vehicle. Kärcher therefore rates the MSR145 mini data logger as very suitable for monitoring pallet shipping, i.e. for measuring vibrations and light impacts (< ±15 g).
For short and more intensive shocks, e.g. 75 g with 8 ms, as can occur during individual shipments, the MSR165 data logger, which is specially recommended for transport monitoring, is superior to the universal MSR145. At 1600/s, the MSR165 allows the user to take significantly more measurements than the MSR145 (50/s); the transport loads can therefore be detected with a much higher resolution. The MSR165's memory capacity of over two million measured values is sufficient to record over 10,000 shocks, and the memory capacity can be expanded to over 1 billion measured values using a microSD card. Also helpful: 32 measured values are saved before the event.
Example measurement from Alfred Kärcher GmbH & Co. KG.
The following diagram illustrates the loads acting on the packaging during a pallet shipment. The packaging was transported from plant 1 to plant 2 and then back again. The packaging was always in a pallet cage.
The events that took place at the respective measurement times are shown below:
At the start, the packaging was first transported to the mesh box and placed in it. This process can therefore be regarded as manual handling. The values marked with frame 1 were recorded. These are therefore within a range of ± 3 g to ± 4 g.
This is followed by a longer phase in which no change in acceleration can be seen. This is due to the fact that the packaging was stored in the mesh box during this period.
In frame 2, various events take place one after the other. First, the pallet cage is loaded into the truck and then transported to plant 2. Once there, the pallet cage is unloaded again and the packaging is manually removed from it and placed in a new pallet cage for the return transport. However, no high impact loads are observed during any of these processes. The maximum acceleration value achieved is four times the acceleration due to gravity.
This is followed by another storage phase. In contrast to the storage in plant 1, however, the data logger records three impact events (marked by circles in the diagram). One reason for this may be that additional packaging has been placed in the pallet cage. If these collide with "packaging A", for example, such an impact can occur. It is also possible that the pallet cage has received an impact that has been transferred to the packaging.
The pallet cage is then loaded back into the truck and transported to plant 1. There, the pallet cage is unloaded and transported manually to the delivery location. The mechanical-dynamic loads determined in the process are characterized by frame 3. The highest impacts of the measurement were determined here. It can also be seen that the data logger's measurement limit of ± 16 g was reached. However, as the packaging was also equipped with a Solve1 logger, it can be determined that an acceleration of more than 20 g was not achieved.
Conclusion
Critical transport events such as shocks, impacts, vibrations, but also temperature fluctuations or changes in air pressure can be precisely recorded with data loggers. If the packaging has been opened or even damaged en route - or if moisture has caused damage - the loggers use appropriate sensors to document even the smallest change with exact time information. Any transport damage is thus detected at an early stage and the events can be fully reconstructed - liability issues can also be objectively assessed. The evaluation of the measurement data also provides valuable basic information, which must also be taken into account in the transport packaging.