TABLE 32: CUTANEOUS PERCEPTION OF RFR
| Authors | Effects Sought or Examined | Exposure Modality | Effects Reported | Notes & Comments | |||||
|---|---|---|---|---|---|---|---|---|---|
| Hendler and Hardy (1960)
Hendler et al. (1963) Hendler (1968) | Sensitivity of the skin of the human forehead to RFR and infrared (IR). | RFR-exposures were: to 0.4-µs, 10-GHz pulses at 2,500 pps, or to 2-µs, 3-GHz pulses at 300 pps. IR-exposures were to a hot plate (black body) held at about 245 °C (emission peak at 5 microns). | The IR data indicated that the best correlate of the reported temperature sensations was the time-rate-of-change of the skin temperature when the skin remained within a few °C of its normal level. The thresholds for this endpoint were between +0.001 to +0.002 °C/s for warm sensation and -0.005 to -0.006 °C/s for cool sensation.
In an IR plot, the increase in surface temperature diminished with exposure time (showing reciprocity), whereas in an RFR plot for 10 GHz, it rose linearly with exposure time. Plots were given of the threshold stimulus intensity versus exposure time for 3 GHz, 10 GHz, and far IR. Reciprocity was evident in all three curves, with the 3-GHz curve above the 10-GHz curve and the latter above the IR curve, results consonant with respective penetration depths. Threshold stimulus intensities for 1-second exposures to 3 GHz, 10 GHz, and IR were about 60, 19, and 5 mW/cm² , respectively. | A central 37-cm² area of the of each subject's forehead was exposed. IR detection was done with a radiometer, using the black-body characteristics of the skin in the IR region. Auditory warning signals were given before either IR or RFR stimulus. On stimulation with IR every 10 seconds during 10-minute sessions, each subject orally reported feeling either a warm, cool, or no sensation. On stimulation with RFR, each subject operated either or neither of two manual switches to record a warm, cool, or no sensation.
| Justesen et al. (1982)
| Warmth thresholds of the human forearm to far-field 2.45-GHz CW RFR and to IR.
| Exposures were for 10 seconds each, at aperiodic intervals of 30 seconds, to 2.45-GHz CW RFR with the forearm parallel to the E-vector.
| Three men and 3 women were subjects for the RFR experiment and 2 of each gender participated in the IR experiment. The ranges of power densities used were 0-70 mW/cm² in 5-mW/cm² steps for RFR, and 0-5.5 mW/cm² in 0.5 mW/cm² steps for IR. The thresholds for RFR perception by the 6 subjects ranged from 15.40 to 44.25 mW/cm² with a mean of 26.74 mW/cm² . The IR thresholds for the 4 subjects ranged from 1.45 to 2.55 mW/cm² , with a mean of 1.74 mW/cm² . The corresponding range of RFR threshold energies was 6.43 to 15.58 J, with a mean of 10.16 J. The IR range was 1.38-2.24 J, with a mean of 1.83 J. Thus, the amount of RFR energy absorbed for threshold stimulation was about five times higher than for IR.
| For exposure, each subject was placed behind an RFR-absorbing partition, with the ventral forearm surface against a 15-cm aperture in the partition. Using an aperture of the same size in a Styrofoam partition, the subjects were similarly exposed to IR from focused quartz lamps. IR and RFR SARs were determined with saline-filled cylindrical balloons secured against the apertures. | |
This is a Department of Defense computer system for authorized use only. DoD computer systems may be monitored for all lawful purposes, including to ensure that their use is authorized, for management of the system, to facilitate against unauthorized access, and to verify security procedures, survivability, and operational security. Using this system constitutes consent to monitoring. All information, including personal information, placed on or sent over this system may be obtained during monitoring. Unauthorized use could result in criminal prosecution.
POC: AFRL/HEDM, (210)536-6816, DSN 240-6816