B.Schmitt mobile and Hytera Mobilfunk now have it in black and white. An examiner from the MPA (Material Testing Institute) has confirmed: the TETRA building radio system DIAMANT 2.0 with the DIB-R5 outdoor base station on the inside and protected with a fire protection housing guarantees object radio coverage in buildings over a period of more than one and a half hours in the event of a fire – and thereby fulfils the requirements for an autonomous BOS radio system in the event of fire. 90 minutes is precisely the critical time that firefighters need in an emergency to gain an idea of the situation in the building, to save lives and to fight the fire.
How was it tested?
The control cabinet with the TETRA building radio system DIAMANT 2.0 from B.Schmitt was installed in the middle of a fire protection cabinet for the fire test and placed in a fire chamber. Shortly before the test setup was set on fire, the testers activated the radio system inside and started recording the test monitoring.
During the fire test, the examiners tested the functionality of the radio system at 5-minute intervals. Using an RF AirAnalyzer from Hytera, they checked the transmitting power of DIAMANT 2.0 including the RMS value. Speech tests were also carried out with two handheld radios.
Fire test result
All functionally necessary parameters were observed. The transmitting power and the RMS value of the DIAMANT 2.0 remained constant over the test period of 90 minutes and even beyond, and conversations via the handheld radios could be held at any time. When the 230V supply was disconnected after 90 minutes, the functionality of the building radio system could be demonstrated for additional minutes even in emergency power mode.
Heat is the biggest challenge
The biggest challenge for the radio technology inside the control cabinet was the heat. During the fire test, the temperature inside the control cabinet with the TETRA building radio system rose to around 47 degrees Celsius. In the fire protection cabinet, the examiners even recorded more than 85 degrees Celsius during the same period.
The fire test has emphasised that the arrangement of the control cabinet within the fire protection cabinet is of major importance in order to be able to withstand the extremely harsh requirements. “It is crucial that the control cabinet with our DIAMANT 2.0 is installed as far away as possible from the walls of the fire protection cabinet. This is the only way to keep the heat transfer between the cabinet walls as low as possible,” explains Patric Wollweber, managing director of B.Schmitt mobile GmbH. “It is just as important that the control cabinet is completely closed in order to control the air circulation and to keep the internal temperature as low as possible. Overall, it depends on the optimal interaction of all technical components.”
Proof of having passed the fire test is a prerequisite for the building inspectorate approval of the radio system including the housing for use as a replacement for an internal plant room by the German Institute for Building Technology (DIBt).
B.Schmitt mobile has received the test certificate for its TETRA building radio system DIAMANT 2.0 with the Hytera DIB-R5 outdoor base station and has therefore obtained approval from the German Institute for Building Technology (DIBt). In addition, the Federal Association of Professional Mobile Communications (PMeV) and the Federal Association for Object Radio in Germany (BODeV) have certified B.Schmitt mobile with their seal of approval for object radio.
BOS building radio systems
Some buildings and structures cannot be penetrated by radio waves from the German BOS network (digital radio from the authorities and organisations with security tasks) or other commercial mobile radio networks – the reasons for this can include reinforced concrete in the building, metal-coated glazing or metal on façades. This affects above all larger special buildings such as public buildings, shopping centres, sports facilities and high-rise buildings. In this case, the installation of an object radio system is mandatory in order to ensure seamless digital radio in the building at all times in the event of an emergency. The building owner or operator is responsible for the construction and proper operation of a property radio system.
About B.Schmitt mobile GmbH
B.Schmitt mobile, based in the German state of Hesse, has been a radio dealer and system house for more than 50 years. As an expert for BOS building radio systems – from planning, installation and commissioning to maintenance – the company has established itself with the TETRA building radio system DIAMANT 2.0 and is a valued partner of Hytera Mobilfunk GmbH.