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G. Spelsberg GmbH & Co. GEOS series enclosures and accessories

DLG-APPROVED: "Ammonia resistance"

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The Approval

The DLG APPROVED quality mark for ‘single, value-deter­mining criteria’ is awarded to technical products that have passed a less comprehensive DLG usability test which is carried out and evaluated to independent and approved criteria. The purpose of this test is to highlight a product’s specific innovative and key features. The test is carried out to criteria that are laid down in the ‘DLG Full Test’ framework for technical products or may include further features and properties that confer a specific value to the product. DLG group of experts defines the minimum standards to be applied to the product and describes the test conditions and procedures as well as the criteria by which the test results are to be evaluated. These parameters reflect the acknowledged state of the art as well as scientific findings and agricultural insights and requirements. After a product has passed the test, a test report is produced and published and the quality mark is awarded to the product and will retain its validity for five years from the daate of award.

The test on ammonia resistance was carried out at the lab to the patented DLG test standard. The aim of
the test was to determine the suitability of the equipment for use in animal buildings and how the equipment performed when exposed to the climate inside animal buildings. The items and materials tested were new
and recently manufactured. The testing scheme applied was the DLG protocol on the testing of ammonia resistance, version 07/2017. No other criteria were tested in this test.

Assessment in brief

The materials supplied for the DLG Approved test were new and recently manufactured. They were tested for their ability to resist the stresses imposed by ammonia. The results show that the materials meet all the requirements to pass this DLG test.

Table 1: Summary of test results

* Evaluation range: + + / + / ◯ / – / – – (◯ = standard)
Parameter tested: Ammonia resistance      
Component Test result Assessment *  
GEOS series Enclosures resistant +
MPI Mounting plate resistant +
MPS Mounting plate resistant +
L EP Insert plate resistant +
ABL Mounting bracket resistant +
MH Bracket and base plate resistant +
L TW Partition resistant +
NS35 Mounting bar resistant +
  Bel Air resistant +

The product

Description and specifications

All materials tested form part of the GEOS series enclosures. Among other applications, the enclosure is installed in animal buildings where it may be exposed to higher concentrations of ammonia.

Table 2: Specifications (manufacturer information)

Series GEOS enclosures  
Measured voltage 1000 V AC, 1500 V DC
Length 300 - 400 mm
Width 300 - 500 mm
Height 180 - 226 mm
Accessories Dimensions   (Length x Width x Height)
MPI Mounting plate 250 - 350 mm x 250 - 450 mm x 5 mm
MPS Mounting plate 250 - 350 mm x 250 - 450 mm x 2 - 5 mm
L EP Insert plate 276 - 376 mm x 276 - 476 mm x 4 mm
ABL Mounting bracket 94,3 mm x 19,9 mm x 40 mm
MH Bracket and base plate 74,9 mm x 31,6 mm x 155,5 mm
L TW Partition 470 mm x 2,5 mm x 156 mm
NS35 Mounting bar Bel Air 450 mm x 35 mm x 7,5 mm

The Method

Ammonia resistance

The ammonia resistance of the materials was determined in a lab test that was carried out to the DLG test standard for agricultural applications. The DLG ammonia resistance lab test measures the ability of the sample to withstand the exposure to animal housing climates over a lifetime of up to 20 years.

To simulate these conditions and this time period, the sample was placed in a climate chamber where it was exposed to the following conditions:

Duration of the test 1500 h
Air temperature 70 °C
Relative humidity 70 %
Ammonia concentration 750 ppm


To assess the ability of the sample to resist NH3, the sample was visually inspected, weighed and its hardness was measured using the Shore durometer. This procedure was applied to at least two samples of each product.

Detailed account of the test results

Ammonia resistance

The enclosures showed no signs of stress or damage by the NH3 gas during the test, but the transparent cover lost its shiny finish. The finish seemed dull and the transparency declined visibly. However, this trans­formation does not affect the functionality of the enclosures, unless a specific application may require a flawless finish. Therefore the DLG assessed the cover as offering ‘limited resistance’. In this context it should be pointed out that the test conditions are very accelerative to simulate long-term conditions and allow testers to make a statement on longevity.

However, in view of the fact that the transformation does not affect the functionality of the component and also in view of the fact that ammonia concentrations are much lower in reality the enclosures as a whole can be assessed as suitable for use in animal buildings. All other parameters tested were found to be within uncertainty or target range. Hence, we can conclude that the materials will sufficiently withstand exposure to NH3 gas as it is the case in pig houses. The test was carried out at an ambient temperature of 70 °C and without an electric or data line being connected to the enclosures, hence without pressure compensation. The manufacturer says that a pressure compensation is provided by the feed line into the enclosures.

Table 3: Impact of NH3 on the enclosures

Component visual inspection Weight Shore hardness Assessment
Enclosures, grey cover with seal not affected < 1,0 % < 3,0 % resistant
Enclosures, transparent cover with seal dull cloudiness < 1,0 % < 6,0 % partially resistant
Series GEOS enclosures       resistant

Table 4: Impact of NH3 on the accessories

Accessories visual inspection Weight Shore hardness Assessment  
MPI Mounting plate no change < 3,0 % < 3,0 % resistant
MPS Mounting plate no change < 3,0 % not tested resistant
L EP Insert plate no change < 3,0 % < 3,0 % resistant
ABL Mounting bracket no change < 3,0 % < 6,0 % resistant
MH Bracket and base plate no change < 3,0 % < 6,0 % resistant
L TW Partition no change < 3,0 % < 3,0 % resistant
NS35 Mounting bar no change < 3,0 % not tested resistant
  Bel Air no change < 3,0 % < 3,0 % resistant


The results of the test show that the GEOS series c/w all accessories meets the DLG test requirement for ammonia resistance for receiving the DLG APPROVED quality mark (scoring “o” or better). This suggests that the model range tested can be considered as resistant to ammonia loaded air in animal houses. No other criteria were tested in this test.

Manufacturer and applicant

Günther Spelsberg GmbH & Co. KG
Im Gewerbepark 1
D-58579 Schalksmühle

Telephone+49 (0)2355 892-0
Telefax +49 (0)2355 892-299

Test implementation

DLG TestService GmbH, Gross-Umstadt location
The tests are conducted on behalf of DLG e.V.


Division head
Dr. Ulrich Rubenschuh

DLG test scope
DLG Approved test “Ammonia resistance” (date of issue 07/2018)

Test engineer
Tommy Pfeifer *

*    Author


DLG TestService GmbH - Groß-Umstadt location • Max-Eyth-Weg 1 64823 Groß-Umstadt Germany • Tel.: +49(0)69 24 788-611 •