The following Studies have been carried out by independent Universities and Institutes.  A full copy of the studies can be obtained by contacting us and detailing which studies you wish to receive.

 Study 1 | Study 2 | Study 3 | Study 4 

1) Wilson, P.J. 1998  -  Brickearth Data  -  Forest Products Journal Vol.49 No.9
"Accuracy of a capacitance-type and three resistance-type pin meters for measuring wood moisture content"

Abstract
The moisture content (MC) of 441 wood samples from 30 batches and 14 species was estimated using one capacitance-type meter (Wagner L612) and three resistance type pin meters, and compared to ovendry MC.  The L612 was the most accurate.  The pin meters, whose data were corrected accurately for wood temperature, gave similar results to each other.  The results were largely unperturbed by the choice of user settings for species/wood density.  The basic (residual) variability of meter readings was similar for the two meter types but the pin meters had a stronger tendency to over- or under estimate MC depending on the batch.  In contrast to the pin meters, the L612 was nondestructive, and quick and easy to use.

Conclusion
In Industry conditions, in timber stored under shelter, the capacitance-type L612 performed better than the three pin meters combined.  It was more accurate, and quicker and easier to use.  Further accuracy comparisons would be of interest, for example in outdoor stored, recently kilned, and laboratory-conditioned timber.

 Study 1 | Study 2 | Study 3 | Study 4 

2) Kemmsies M., 1998  -  Swedish National Testing and Research Institute
"Comparative testing of Wagner L612, electrical resistance meters, and the ovendry determination of wood moisture content on Norway Spruce and Scots Pine"

Summary
A test sequence was carried out to compare the accuracy of hand-held wood moisture meters based on the principle of electrical resistance (on-site mill readings and a calibrated meter), and Wagner’s L612 capacitance moisture meter (mill readings). Results were compared to those provided by the oven-dry test method, which served as a benchmark value for the comparisons.

Wood species tested were Swedish Norway spruce (Picea abies) and Scots pine (Pinus sylvestris), the two most common coniferous species in Scandinavia. Two hundred samples per wood species were collected at three geographically distinct sawmills in Sweden, both in southern and northern Sweden.

Comments and summary
On average the Wagner L612 Electronic Wave meter performed better than resistance meters under normal operating mill conditions. The wood m.c. estimate provided by the Wagner L612 meter was better for spruce than for pine.

The study also shows that a considerable difference in wood m.c. estimates can be achieved with electrical resistance meters, depending whether the meter is used properly or improperly. The best estimates in this study were shown by the use of resistance meters when used under controlled conditions at the SP.

The two most common mistakes thought to be the cause of these disparaging results when using electrical resistance meters are:

• It must be ensured that the pins are driven in a certain thickness into the board (0,2 X the thickness of the board in Sweden, or 0,3 X the thickness of the board according to the European norm draft), something which is not always practical or easy to follow in a consequent manner under field conditions. Often an experienced estimate at the correct pin depth is carried out by the mill operator.
• That the meter be adjusted to the wood temperature, and not to the air temperature. The wood temperature was controlled after the mill operator had carried out his measurements, an overestimate in the wood temperature by up to 10 °C being noted. This situation can be especially misleading in areas of the country and during seasons where temperatures vary strongly.

Despite the m.c. underestimate shown by the Wagner L612 meter at m.c.'s ³ 17 %, for the combined mean results for spruce and pine the Wagner L612 meter showed 50 % more readings within 0,5% of oven-dry m.c., and 12 % more readings within 1 % of oven-dry m.c. as compared to the resistance meters used by operators in mill conditions (see Figure 3).

The Wagner L612 meter was easy to handle, and in this study was capable of taking approximately four measurements within the same time that one measurement could be registered with a resistance meter. Unlike resistance meters, the Wagner L612 meter required no air or wood temperature adjustment, nor did board thickness - in the sampled thickness range - have to be taken into consideration. This made the Wagner L612 meter practical to use in operational conditions, with less likelihood of operator induced bias.

It is, however, important that the SG settings in the Wagner L612 be carefully selected and programmed to the species in question, as recommended by the manufacturer. It is furthermore recommended that the SG setting be specific to the material available in the region the wood comes from. Based on the data collected in this study, the SG settings for Swedish Scots pine (Pinus sylvestris) are recommended be 0,42 in southern Sweden and 0,43 in northern Sweden; and that SG settings for Swedish Norway spruce (Abies picea) are recommended to be 0,36.

 Study 1 | Study 2 | Study 3 | Study 4 

3) Guzenda R, Olek W. 1998  -  Agricultural University of Poznan.
"Comparative measurements of moisture content of Scots pine and European oak with the use of Wagner L612 meter, resistance meters and oven-dry method"

Introduction
The report contains results of comparative measurements of sawn timber moisture content. The following measuring methods were used:

• oven-dry (measurements were performed in the laboratory of the Department),
• resistance (readings were made with meters originally used in companies),
• capacitance (readings were made with the use of the Wagner L612 meter).

Measurements were made for sawn timber of the following species: Scots pine (Pinus sylvestris L.) and European oak (Quercus robur L.) Its thickness was 25, 38 and 50 mm. Timber was previously pre-dried or kiln dried to moisture contents below the Fiber Saturation Point.
The report gives also results of the analysis aiming to find the optimum values of SG settings for Scots pine and European oak in Polish conditions.

Final remarks and conclusions
The Wagner L612 meter was easy to operate. The meter also enabled to make much more readings of moisture content in the same time in comparison to resistance meters. During the optimising analysis there was observed the need to use two different SG settings at different ranges of moisture contents in order to obtain the best accuracy of the meter. In such a case the L612 meter is more accurate as resistance meters. Taking into account that the L612 is fully nondestructive meter of timber moisture content it can be regarded as an alternative and very valuable system for the moisture content determination especially when good accuracy is required without timber damaging.

 Study 1 | Study 2 | Study 3 | Study 4 

 4) A study by the University of Florence (Forestry Plantation and Technology Institute) and by CNR/IRL (Wood Research Institute, Florence) to determine the accuracy of Wagner Moisture Meters as compared to the traditional Pin (Resistance) Meters when used in Industrial Conditions.

Author; Leonardo Maestripieri. Final Year MSc

Supervisor Professor Uzielli

The Use of Wagner Handheld Moisture Meters.

Wagner Moisture Meters are well-known amongst professionals for their accuracy, reliability and durability under industrial conditions of use. The type of sensor used gives an accurate and completely non-destructive read-out of the moisture content of the wood. In addition, the fact that these sensors are unaffected by the ambient temperature and the actual size of the wood being measured, means they are particularly suitable for fast and efficient quality control, giving the user peace of mind that the "moisture" problem can be controlled both easily and economically. For these reasons Wagner Moisture Meters are most widely used throughout the USA and Canada and are rapidly becoming established in Europe.

However, the nature and specific requirements of Italian companies are not always comparable with those of companies in other countries. In order to determine whether Wagner Moisture Meters offer the same advantages of accuracy and reliability under typical conditions of use in Italian companies, a study was commissioned from the University of Florence (Forestry Plantation and Technology Institute) and from the CNR/IRL (Wood Research Institute, Florence). Some parts of the study are still being carried out, but some results have already been made available.

Accuracy and Reliability under Industrial Conditions

The definitive reference for measuring the Moisture Content of wood is the gravimetric method, which consists in weighing the sample, putting it in a ventilated kiln at 103±2(C until it reaches a constant weight) and then calculating the humidity by the difference in weight. This method is described in the UNI standard 9091/2 and is only infrequently used in industrial conditions, because of its destructive nature. The majority of Italian companies use Resistance Meters ( Pin Meters), which are inserted into the wood and measure its resistance to the passage of an electric current).

In order to compare the accuracy and reliability of Wagner Handmeters, approximately 200 measurements were taken at 8 different companies which work with solid wood (parquet, window and door frames, packaging and panels), using both the device operated by the company and the Wagner device which was most similar in size and performance to this and comparing the values with those obtained by means of the gravimetric method on the same pieces. The operating conditions were as close as possible to those adopted by the company for their controls (measuring position, calibration of the instruments, etc.).

During the course of the work, the greater ease and speed of use of Wagner devices could be noted, and their accuracy exceeded that of the Resistance Meters. The following graph shows how, out of a total of 200 measurements taken, the Wagner devices gave values closer to those obtained by the gravimetric method in a greater percentage of cases. For example, allowing an admissible deviation in humidity of 1% between the read-out on the device and the gravimetric result, Wagner meters were accurate 47 times out of 100, whilst the Pin Meters scored 42 out of 100.

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