Volume spirometers need automated internal temperature sensors.
Spirometer temperature was measured automatically during all years of the Lung Health Study. Short- and long-term changes in temperature were analyzed for the 23 dry-rolling-seal volume spirometers used at the 10 clinical centers involved in the study. Within-test-session spirometer temperature increased a mean of 0.3 degrees C, and as much as 3.0 degrees C during methacholine challenge testing. The maximal change in spirometer temperature during a test day exceeded 4 degrees C more than 5% of the time. Month-to-month changes of more than 15 degrees C were not uncommon. If ambient temperature had been assumed to apply to all maneuvers and used for BTPS corrections, FEV1, and FVC measurement errors of up to 6% would have occurred. When using volume spirometers, the temperature of air inside the spirometer should be measured accurately during each breathing maneuver.
Johnson
L R
LR
Lung Health Study Research Group, Oregon Health Sciences University, Portland.
Enright
P L
PL
Voelker
H T
HT
Tashkin
D P
DP
D001985:Bronchial Provocation Tests; D005069:Evaluation Studies as Topic; D005541:Forced Expiratory Volume; D006801:Humans; D013147:Spirometry / Q000295:instrumentation* / Q000592:standards / Q000706:statistics & numerical data; D013696:Temperature; D013821:Thermometers / Q000592:standards / Q000706:statistics & numerical data; D013997:Time Factors; D014481:United States; D014797:Vital Capacity