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Moisture-proof diffuser luminaire AMPHIBIA PM

DLG-APPROVED „Resistance to ammonia“

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The approval

A test mark “DLG-APPROVED for individual criteria” is awarded for agricultural products which have successfully fulfilled a scope-reduced usability testing conducted by DLG according to independent and recognized evaluation criteria. The test is intended to highlight particular innovations and key criteria of 
the test object. The test may contain criteria from the DLG test scope for overall tests, or focus on other value-determining characteristics and properties of the test subject. The minimum requirements, test conditions and procedures as well as the evaluation bases of the test results will be specified in consultation with an expert group of DLG. They correspond to the recognized rules of technology, as well as scientific and agricultural knowledge and requirements. The successful testing is concluded with the publication of a test report, as well as the awarding of the test mark which is valid for 
five years from the date of awarding.

The ammonia resistance test was performed as a laboratory test according to the patented DLG test standard. This test is intended to determine the suitability of equipment for animal living areas to withstand the impact of animal environments.

Other critera have not been assessed.

Assessment – Brief Summary

The moisture-proof diffuser luminaire AMPHIBIA PM has successfully com­pleted the DLG test for ammonia resistance. According to this result, it can be assumed that these luminaires are resistant to the typical environmental conditions of animal living areas and that no accelerated reduction of the product lifetime will occur. In addition, the moisture-proof diffuser luminaire AMPHIBIA PM was operated actively in the chamber for the entirety of the test. No product damage was observed here.

Table 1: Assessment in brief

Ammonia resistance
Preservation of the luminous flux

* The DLG test framework provides the following options in its evaluation schemes:
■ ■ ■ or better = meets, exceeds or  clearly exceeds the specified DLG standard,  ■ ■ = meets the legal re­quire­ments for marketability,  = failed

The Product

Description and technical data

The moisture-proof diffuser luminaire AMPHIBIA PM tested here is suitable for use in animal living areas. The material of the housing consists of PMMA.

Table 2: Technical data (according to manufacturer)

Electrical connection 
Voltage220-240 V
Frequency0/50/60 Hz
Rated input power31 W
Dimension and weight 
Width/length92 mm/1,110 mm
Height90 mm
Weight2.31 kg
Additional technical data 
Number of LED modules2
Housing materialPMMA
Colour temperature (CCT)4000 K
Light angleWide Beam
Luminous efficacy149 lm/W

The Method

Resistance to ammonia

The ammonia resistance of the moisture-proof diffuser luminaire AMPHIBIA PM was determined by a laboratory test with one luminaire according to the patented DLG test standard for agricultural use. The laboratory test is designed to replicate the conditions of a usage period of about 10 years exposure 
to animal living areas. 

The test was carried out in a climate chamber under the following climate conditions:

Test duration1500 h
Air temperature70 °C
Relative humidity70 %
Ammonia concentration750 ppm

For assessing the ammonia resistance, each luminaire was examined visually, gravimetrically and the plastic parts additionally through measurement of the hardness (Shore D) before and after the climate testing.

The luminaires have additionally been following a cycle of operation predefined by DLG (3 hours on, 1 hour off) in order to evaluate any thermal impacts caused by switch-on and -off procedures during ammonia fumigation. Furthermore the luminous flux was measured according to DIN EN 13032 before and after the fumigation in order to get additional information regarding the aging process.

In order to avoid overheating (> 70 °C), the luminaires could be operated at a reduced power level during the testing period.

For the approval of all luminaires in table 2, the moisture-proof diffuser luminaire “AMPHIBIA AMP S 4600-840 PM WB EVG, 1.1 m long” has been used. After the tests, the luminaires underwent visual examination to a reference sample that was identical in construction.

The Test Results in Detail

Resistance to ammonia

Visual test
The comparative visual examination after the ammonia exposure has shown minor discolorations at the inside of the luminaire housing. There were few discolorations on the outside of the housing. The deformation at the housing kept within limits.

It cannot be ruled out that a limited ammount of ammonium compounds might enter the luminaire housing. 
Also in this case, no negative impact on the luminaire performance needs to be expected.

The defects are rated as insignificant.

Gravimetric test
Weight comparisions before and after the ammonia fumigation have not shown any measurable increases 
or decreases in weight.

Hardness test
During the hardness test (Shore D) no measurable changes were observed. All determined changes were within the measurement incertainty. 

Functional test
No defects were observed. All luminaires worked well after the conducted tests.

Preservation of the luminous flux
After completion of the test the luminaire still had a luminous flux of 95.5 %.

Based on the results of these tested parameters, the luminaire is evaluated as resistant to ammonia.


The results show that the moisture-proof diffuser luminaire AMPHIBIA PM fulfills the testing requirements for ammonia resistance and thus receives the test mark DLG-Approved. It can be expected that the luminaire is resistant to ammonical air in animal living areas and that no accelerated reduction of the product lifetime occurs. The moisture-proof diffuser luminaire AMPHIBIA PM was operated both passively and actively during the ammonia fumigation in the test chamber and passed both tests successfully.Other critera have not been assessed.

Applicant and Test implementation

Manufacturer and Applicant

Zumtobel Lighting GmbH
Schweizer Strasse 30
6851 Dornbirn

Phone +43 (0)5572 390-0 

Testing agency

DLG TestService GmbH, Gross-Umstadt location, Germany

The tests are conducted on behalf of DLG e.V.

DLG test scope
DLG-approved single criteria test 
“Leuchtsysteme in Ställen“ (current as of 03/2021)


Division head
Dr. Ulrich Rubenschuh

Test engineer(s)
Dipl-Ing (FH) Tommy Pfeifer *

Photometric laboratory
Photometrik GmbH, Einsteinstraße 24
64859 Eppertshausen, Germany

* Author


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