The subject held the phone in soft contact with the pinna with the phone touching only the uppermost part of the cheek, hence there was a small gap between the phone and most of the cheek. The display of the phone was masked, and a plastic bag, taped to the top of the phone, covered the load and the cable.
The following power conditions were used: mobile phone switched off, mobile phone switched on at minimum and at maximum output power. All three conditions were applied both with the phone in the normal configuration and with the antenna being replaced by a 50 Ohm load to absorb the RF energy. When the 50 Ohm load was used, the SAR did not exceed the background level. The study was conducted on five consecutive days, each with six 30 min exposuresessions. The order of the different exposure conditions was changed (double-blind) from day to day. After five days, each condition had been presented at all the different times of the day. In addition, each condition had been preceded by each of the other conditions.
SAR values indicated are spatial peak values at maximum output power.
Measurement and calculation details
The average output power was measured by a power meter in series with a powersensor coupled to the antenna gate of the phone. SAR measurements have been made by Wilen et al. (see reference article) using the same test phone as in this study.
Wilen J et al.
Subjective symptoms among mobile phone users - A consequence of absorption of radiofrequency fields?