The increase in the urban population is impacting the environment in several ways, including air pollution due to emissions from automobiles and industry. The reduction of air pollution requires reliable and detailed information regarding air pollution levels. Broad deployment of sensors can provide such information that, in turn, can be used for the establishment of mitigating and regulating acts. However, a prerequisite of such a deployment strategy is using highly durable sensors. The sensors must be able to operate for long periods of time under severe conditions such as high humidity, solar radiation, and dust. In recent years, there has been an ongoing effort to ruggedize sensors for industrial applications with an emphasis on elevated temperature, humidity, and pressure. Some of these developments are adapted for urban air sensing applications. However, protection from dust is based on filters that have not been modified in the last few decades. Such filters clog over time, thus requiring frequent replacement. This editorial presents the need for a consumable-free dust removal device that provides consistent performance without affecting the sensing process. A specific solution for removing dust using a cyclone dust separator is presented. The cyclone dust separator is implemented as an add-on module to protect commercially available sensors.

The development and testing of a module that removes dust from air based on cyclone technology and its coupling to a chemical detector are described. This development was performed in a laboratory facility that is capable of simulating a harsh environment in which the target material can be mixed with dust at controlled climatic conditions. The size-dependent removal efficiency of the module was tested at different operational conditions. For dust particles of 5 µm and higher, removal efficiency is about 100%. The efficiency for smaller particles is lower, and the overall efficiency is 97%. No significant adverse effect on the detector (flame photometric detector) performance at low to moderate target material concentrations (100 µg/m³), even at high dust concentration, is observed. The cyclone operation does not require the use of consumable and its maintenance is minimal. Power consumption is 15W, which is acceptable for a fixed site or car transportable system and can be further reduced for the handheld version.

The development and study of a protective module that removes dust from an air stream based on improved cyclone technology (cyclone separator – CSR) are described. In previous work, we developed a standard CSR and coupled it to a chemical detector. This coupling provides an excellent solution for a few hours of operation required for the detection of hazardous materials in cases of emergency. However, environmental monitoring requires to prolong operation, which requires handling large amounts of dust. This can be accomplished by improving the CSR and increasing its capability to remove fine dust particles that may interfere with the proper operation of the chemical detector and other electronic devices that are often required in environmental applications. Performance is improved by adding low airflow pumping-out from the CSR dustbin. Dust removal efficiency improves by factor 3–7 for small particles, which is valuable for prolonging outdoor operation. The improved CSR performances are constant over time, which is adventurous for prolonging operation of sensitive equipment in a harsh environment.

Calorimetric dosimetry is based on exposing an absorbing body to a radiation field. The energy deposited in the absorber is determined by measuring the absorber temperature rise. We explored the feasibility for obtaining measurable dose rates by using a thin (240 μm ) lead (Pb) plate, a six-fold aluminum/silicon thermopile, and a tungsten W anode 70-125 kV X-ray source. The plate/thermopile thermal coupling was based on a thin layer of thermal grease. Response signals were measured for different current and voltage operations of the X-ray tube at different distances. 20 μV signal were measured for 125 kV, 20 mA tube operation at a distance of 22 cm. The obtained signals were however consistently smaller than expected by about an order of magnitude. We suggest that improved thermal insulation between the lead plate plus thermopile, and the other device constituent elements, would allow obtaining much higher response signals, making it a worthy candidate for X-ray dosimetry.