As part of the DFG project "MeDKet", the Leibniz Centre for Agricultural Landscape Research (ZALF) in Müncheberg, together with the University of Bonn and Forschungszentrum Jülich, wants to investigate the microbial ecology and biogeochemistry of the dynamics of the climate-relevant trace gas methane (CH4) in small-scale wetlands, also known as Sölle, which are located in the middle of arable land and are temporarily dammed. For this purpose, it is necessary to record the methane concentration on these wetlands during longer-term measurement campaigns in order to precisely determine the CH4 concentration profile in the ground-level air and to calculate the CH4 fluxes. This requires a precise, easy-to-transport (mobile) CH4 gas analyzer that reliably functions (field-compatible) under field conditions.

As part of the DFG project "MeDKet", the Leibniz Centre for Agricultural Landscape Research (ZALF) in Müncheberg, together with the University of Bonn and Forschungszentrum Jülich, wants to investigate the microbial ecology and biogeochemistry of the dynamics of the climate-relevant trace gas methane (CH4) in small-scale wetlands, also known as Sölle, which are located in the middle of arable land and are temporarily dammed. For this purpose, it is necessary to record the methane concentration on these wetlands during longer-term measurement campaigns in order to precisely determine the CH4 concentration profile in the ground-level air and to calculate the CH4 fluxes. This requires a precise, easy-to-transport (mobile) CH4 gas analyzer that reliably functions (field-compatible) under field conditions. To carry out the measurements, it is planned to connect the CH4 analyzer via hose connections to a special profile measuring system or to automatic gas hood measuring systems. During the measurements, the change in the CH4 concentration will be continuously recorded and recorded with high temporal resolution. The data collected using the CH4 gas analyzer must be continuously transferred to an existing data logger (Campbell Scientific) and stored there simultaneously.

Therefore, a CH4 gas analyzer is to be procured, which must have the following performance characteristics (minimum requirements):

specifications

- Simultaneous detection of the concentration of gases CH4 and water vapour (H2O) in air

- Field suitability: Portable (<10 kg), guarantee of undisturbed measurements despite small vibrations due to the movements in the field, several hours (min. 2 h) battery operation necessary, battery change in the field must be possible, splash-proof

- Power supply: 220 volts (mains operation), 12-15 volts (battery operation)

- Precision of CH4 concentration measurement at a measurement time of 1 s: <100 ppt

- Measuring range CH4 concentration: 10 ppb to 10,000 ppm

- Measuring frequency: Variably adjustable between 2 s-1 and 1 min-1

- Response time: up to 1 s, variably adjustable

- Maximum drift: 1-2 ppb CH4 or 0.1% over the entire temperature range over 24 hours

- Interfaces: Wi-Fi, RS-232, USB, Ethernet, analog output

- Temperature range of the air samples: 5 to 40 o C

- External connections for air hoses (inlet and outlet)

- Record, control and store data in real time

- Possibility to quickly calibrate the measuring system on site using calibration gas mixtures.

The customer demands an appropriate manufacturer's warranty, including exchange or repair. Within Germany, the exchange takes place via a pick-up and return service. Telephone support must be guaranteed. The contractor must ensure that the recommissioning of the analyser is ensured within two months.

The CH4 gas analyzer should be supplied in full, i.e. all accessories required for smooth operation and evaluation (e.B ancillary devices, cables, hose connections, interfaces, software, etc.) must be taken into account in the offer in order to avoid subsequent procurement.

Any questions about the specifications must be asked in writing about the Brandenburg procurement marketplace. After receipt of the requests, they will be processed as soon as possible.

The submitted offer must contain:

- Signed specifications

- Signed offer letter

- Delivery time information

- Performance and technical parameters of the system

- Warranty/guarantee: information on the duration and conditions

- Information about the expected maintenance intervals/follow-up costs