4. Installing AX500#
Location Selection Guidelines#
Location plays an important role in measurements of any kind. Take a common thermometer as an example. The temperature reading will be different in a shaded area under a tree canopy in a park compared to a reading taken on nearby pavement a few meters away. Both readings will also differ from a reading taken on the roof of a building. Most likely, none of these measurements will correspond exactly to the official temperature reading for that city provided by the local meteorological authority.
This has nothing to do with sensor accuracy, but everything to do with location selection. All of these readings are correct for their respective locations, but they may not be representative of the wider area. The same principle applies to temperature, humidity, gas concentration, and any other environmental parameter measured in nature.
When it comes to air quality monitoring, the situation becomes even more complex. Not only does the concentration of pollutant gases vary depending on location, but there are also other factors that affect sensor performance, such as temperature, humidity, wind, and other environmental conditions. Therefore, great attention must be given to selecting an appropriate location for installing the meter.
Choosing a Location#
Ideally, the meter should be placed a few meters above the ground on a pole, facing north if possible, and in the shade.
High temperatures have the greatest impact on electrochemical gas sensor performance. This is the main reason why building walls, rooftops, and similar locations should generally be avoided. If it is not possible to install the meter on a pole, and a wall is the only available option, then a north-facing wall should be selected to ensure that the station remains in the shade for most of the day.
In general, select a location that is accessible to service technicians using ladders, preferably at a height of 2–5 m. If the station is installed at the top of a 12 m pole or high on a building wall, even minor maintenance tasks, such as cleaning or electrochemical sensor replacement, may require hiring a crane and stopping traffic. This unnecessarily increases maintenance costs.
The sensor should be placed out of reach of vandals, preferably at a height greater than 2 m. However, it should still be installed in a publicly accessible area, not in a fenced zone or on a locked rooftop. Restricted access complicates maintenance tasks, as they must then be coordinated with the respective property owners.
If the meter must be installed on a rooftop, select a location with good airflow and place the station as far away from the roof surface as possible. Also make sure there are no transmitting antennas, such as cell towers, or external air-conditioning units nearby.
AX500 can be installed on Ø 20–60 mm pole mast, wall, or support arm with mounting bracket.
The recommended installation height is 2–5 m.
Preparation#
Prior to installation, all protective materials both from outside and inside of the station must be removed. Please make sure that all wrapping foils, bubble wrappings, foams and cardboards are removed and that all ventilation and sampling ducts are clear. Inspect the station for possible damage in transport.