Sampling of a broad range of chemicals using a handheld sampler body, having a sample screen in a sampling cassette; where a sample screen housing further consists of a locking arm arrestor body, where, the locking arm arrestor body including a draw tube, and where the sampling screen can be positioned in either a retracted or extended positioned regarding a sample access face. The protruding member includes at least a cleaning nozzle for cleaning the forward viewing observation section andor the side viewing observation section. These starch coatings are adherent to the hydrophobic plastic surfaces under both wet and dry conditions, and they permit the surfaces to be uniformly wet with water. The pixel driving signals is outputted. The method includes directing a beam of coherent radiation to the object, scanning the beam of radiation over an angle in or out of a plane of incidence relative to the object, and imaging scattered radiation from the object on the detection device.