Yes. Testing is conducted using a vacuum pump and an DNPH absorption tube. The pump operates for about an hour. The tube sample is sent to a lab for analysis to determine the concentration of formaldehyde in the air. Indoor levels are then compared to NIOSH and other regulatory exposure guidance levels. Because of the very low NIOSH recommended exposure level (REL) of 16 parts per billion (ppb), samples are taken onto DNPH tubes. The samples are analyzed by high performance liquid chromatography (HPLC, method NIOSH 2016). We do not recommend that a direct-reading hand-held instrument be used.