Perception of heavy work operations by tank truck drivers.

Seven male tank truck drivers were followed for about 3 h during ordinary work. They rated the perception of heavy work operations on Borg's CR-10 scale. The heart rates were monitored every minute. The hose was pulled out an average of 22.3 m and the corresponding mean rating was 3.2, a little above 'Moderate' on the CR-10 scale. The heart rate averaged 137 beats/min at the end of this operation. When transforming the physiological parameter heart rate to a subjective strain intensity, surprisingly high agreement was obtained between the results from the field study and the predicted ratings. By transforming ordinally scaled data from another study to a scale with ratio properties, the results could be compared with this study. Good agreement was found between the variables.