international 3 Nesta Se Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Final Report- -Objective E, Task 8 December 1986 200 AN EXPERIMENT TO EXAMINE THE POSSIBLE EXISTENCE OF REMOTE ACTION EFFECTS IN PIEZOELECTRIC STRAIN GAUGES By:  G, SCOTT HUBBARD SRI International JULIAN D, ISAACS John F. Kennedy University Prepared for: PETER J. McNELIS, DSW CONTRACTING OFFICER’S TECHNICAL REPRESENTATIVE 333 Ravenswood Avenue Mento Park, California 94025 U.S.A. (415) 326-6200 Cable: SRI INTL MPK TWX: 910-373-2046 rae Kepreved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
ere “lf iN SN atio! inter’ \ .ADBEO Lem (R) ed For Release 2001/03/07 : CIA-RDP96-00789R002200100001 -6 Final Report--Objective E, Task 8 December 1986 Covering the Period 1 October 1985 to 30 September 1986 . AN EXPERIMENT TO EXAMINE THE POSSIBLE EXISTENCE OF REMOTE ACTION EFFECTS IN PIEZOELECTRIC STRAIN GAUGES By:  G. SCOTT HUBBARD SRI International JULIAN D. ISAACS John F. Kennedy University Prepared for: PETER J. McNELIS, DSW CONTRACTING OFFICER'S TECHNICAL REPRESENTATIVE SRI Project 1291 Approved by: ROBERT S. LEONARD, Executive Director Geoscience and Engineering Center 333 Ravenswood Avenue * Menlo Park, California 94025 ° U.S.A. (415) 326-6200 - Cable: SRI INTL MPK ° TWX: 910-373-2046 ved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 ABSTRACT Five individuals designated by researchers from JFK University have participated in a series of remote action (RA) experiments conducted at SRI International. Each participant was asked to influence one of a pair of piezoelectric strain gauges, operating in differential mode, in order to produce an event above a predetermined threshold. Under those conditions, one of the participants produced a total of 11 signals above threshold. No equivalent, uncorrelated events above threshold were detected in control periods. Known sources of electromagnetic, acoustic, mechanical, infrared disturbance were considered and wherever possible controlled, minimized, or measured. However, some potential, but unlikely, sources of artifact such as cosmic rays or low-frequency magnetic fields were excluded from consideration in this initial series of experiments. The preliminary nature of these sessions cannot be stressed too strongly, especially because all possible sources of artifact have not been excluded. Nonetheless, our conclusion at this time is that sufficient data have been collected to warrant further investigation. iil Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 TABLE OF CONTENTS ABSTRACT coc ccc ee ee beeen eee nee EE EEE DEE eee E EE EEE ET EE EEE ES iii LIST OF ILLUSTRATIONS AND TABLES ..... eee eee eee rte e teen eens vii EXECUTIVE SUMMARY oo... ce ccc eee ee te eee eee nee Eee eee ix I INTRODUCTION oo. cece cee eee eee eee teen eee nee ree 1 II METHOD OF APPROACH 2... ccc cee ee te ete eee eee tne 3 A. Participant Selection and Training ©... 0. ccc s eee eee eee tenes 3 B. Hypotheses and Variables 6.0.01... cece ee eee eee ee een eee eee eens 3 C. Hardware Construction 00... 0. ccc eee ee ee eee ene eee tae 5 III RESULTS AND DISCUSSION ... ccc cece ect eee eee ence eens 17 A. Individual Results... 0... cece cee eee eee eee ee eee eet 17 B. Control Trials... . cc ee tee tee ete eee teen nees 20 C. Possible Sources of Experimental Artifact ....... See eee eee eee 20 IV CONCLUSIONS coc ccc ee ee ee een ee tet eee een neta 27 APPENDIX A--STRAIN GAUGE REMOTE ACTION SCREENING DEVICE .........- 29 APPENDIX B--ENGINEERING CONSIDERATIONS AND CONSTRUCTION DETAILS OF A PIEZOELECTRIC SENSOR SYSTEM .......-. 00s eee 35 APPENDIX C--FINAL REPORT JFK 1986 ACTION RESEARCH ACTIVITIES ........ 45 Vv Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 LIST OF ILLUSTRATIONS AND TABLES FIGURE 1 Functional Diagram of RA Apparatus ..... sec eee cere eee tenner teen enna 7 2 RA Apparatus for PZT Experiment .... 0. eee eee reece eet teen renter ener enes 8 3 Sensor Enclosure (Open) .... cscs eee eect eee tere n nee tenet teen eee es 10 4 Sensor Enclosure (Closed) 01... : sec e reece eect eee e eee e een t ene a nec en ens 11 5 Schematic of Experimental Area for PZT RA... cece eee reer e eee nner ness 14 6 October, 1986, 10:38 a.m., Participant: 032 ©... ce csc ee ee ee eee e eee eee nees 19 7 Typical Control-Session Data ........eee cece eee e rere eee eee nee n ener ees 21 C=1 Screening Results ..... ccc c cee eee ee eee tent eee eet e enn e ener seers §5 C-2 Participant Piezo-RA Training Sessions .. 1... sere e cece enter eee e eee n eens 63 TABLE 1 Table of Results oc... cece cee eee teeter rete eee ene e eee enn nas 17 vil Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 EXECUTIVE SUMMARY For over a hundred years, reports have appeared in the psychical literature that claim interactions with physical apparatus by mental means alone. If true, such effects will have far-reaching implications. The most direct way to examine this purported phenomenon was to attempt to replicate a claimed effect in our laboratories at SRI International. We began the process of selecting a candidate experiment by first reviewing published laboratory research on remote action (RA)*, placing particular emphasis on recent work which appeared to utilize modern instrumentation.t From our review of the literature, we selected as the most promising experiment, work claiming an interaction with a piezoelectric strain gauge. The basis for our selection was threefold: (1) A nonstatistical effect was claimed, (2) effects were supposedly produced with the subject at a distance from the sensor, and (3) a method of subject selection and training was claimed. In the published reports, a piezoelectric strain-gauge crystal was suspended several meters from the subject. The experimenter claimed that several RA “agents” could consistently produce signals, by mental means alone, which were at least five times the background noise level. Occasional events of as much as 100 times background were also claimed. Although other experimenters have also reported nonstatistical RA effects, we were favorably impressed by the emphasis on artifact detection, at least within an extremely limited equipment budget. In subsequent conversations, the experimenter, J. Isaacs, was very willing to discuss additional potential sources of artifact and methods of control. We formulated a “joint-venture” approach to replicating these claims by awarding a subcontract to John F. Kennedy (JFK) University where J. Isaacs is currently teaching. The task was to screen, assess, train and make available to SRI International promising RA subjects. SRI International retained the task of designing and constructing all experimental hardware. In addition, a series of trials that would be conducted at SRI, under SRI’s supervision, were required at the end of the contract year. We agreed in advance that the “In the parapsychological literature, such effects are usually associated with the term psychokinesis (PK). However, to be consistent and parallel with remote viewing, we have adopted the term remote action. t Radin, D. I., May, E. C., and Thomson, M. J., “Psi Experiments with Random Number Generators: Meta-Analysis Part I," Proceedings of the 28th Annual onvention of the Parapsychological Association, pp. 199-234, Tufts University, Meford, MA (August 1985). ix Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 outcome of those trials would determine whether the evidence was sufficient to warrant proceeding with further experiments. In considering the problem of validating (or invalidating) controversial claims for the existence of paranormal phenomena, SRI recognized two distinct but related, obstacles: (1) No single experiment, no matter how impressive the results, could serve to prove or disprove the existence of RA, and (2) no single initial experiment, no matter how cleverly contrived, could claim to have eliminated or controlled all possible sources of artifactual data. This realization prompted us to adopt a modest goal that we believe is realistic as well as cost effective: We required the hardware and protocols to be sufficiently rigorous such that the presence of any uncorrelated events would warrant continued investigations. Our working definition of “uncorrelated events” was any signal that could not be ascribed to a source normally occurring in the laboratory environment. We did not believe that, at that time, there was sufficient evidence of an RA effect to justify the enormous expenditure of funds and effort required to address every conceivable source of artifact. Our null hypothesis was that no uncorrelated events should be detected, at least for those factors with a routine origin. At no time did we conceive of this effort as “proof” of the existence of RA. Examples of such REMEDY Battery power for critical components, fiber-optic signal links, shielded enclosures sources of artifact and the method of control are: SOURCE ac-line transients Audible~frequency acoustic artifacts Sensor isolation in another room, enclosed sensors, audio taping of all sessions Motor-frequency (30-Hz) mechanical Three types of vibration—-damping vibrations mounts for isolation above 10 Hz EM]I-shielded sensor enclosures and windows A total of 20 trials, each lasting about 90 minutes, were conducted at SRI. Five subjects rf transmissions provided by JFK participated in those experiments. During those trials we detected 11 events that exceeded our determined threshold (six times the noise background) and that did not correlate with any of the sources of artifact we examined. In approximately 30 hours of control trials, conducted under the same circumstances except for the absence of humans, no equivalent uncorrelated events were recorded. As a consequence we concluded that we had collected sufficient evidence to justify investigating this phenomenon further. Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 am WA es Na Al Sa |
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 I INTRODUCTION The overall objective of this experiment was to determine whether remote action (RA) effects can be induced in a piezoelectric (PZT) strain gauge.* The parapsychological literature usually refers to mental effects on material objects as psychokinesis (often abbreviated PK). However, for the balance of this report we shall refer to these putative effects as remote action. In general, these types of RA experiments consist of four basic elements: (1) Some system or apparatus (often a transducer) the output of which is to be affected. (2) An individual who intends to “modify” by mental means alone the output of the apparatus. (3) A feedback mechanism that displays the output of the apparatus either in real-time or after the session. . (4) Ana priori defined analysis procedure. A single trial that encompasses these elements might proceed as follows: The apparatus has been previously actuated, and baseline data collection has been taken in advance of the effort period. In most experiments, a sequence of effort and rest periods then follows when the participant is present. The data record is then displayed to the participant as feedback, and where appropriate, some statistical quantity such as a simple z-score is computed. During a period after the participant has departed, additional control or baseline trials are taken to determine the “normal” characteristics of the apparatus. RA studies have traditionally been divided into two categories: (1) statistical experiments (sometimes called micro-RA) in which small effects are observed over many thousands of samples, and Macro-RA experiments in which large effects were claimed, usually on the basis of a very few trials. Although the statistical experiments have generally been the more rigorous in both protocol and hardware design, interpretation of the results is difficult. In any study in which the test of the null hypothesis is statistical, a causal relationship cannot be * This report constitutes Objective A, Task 8, “An Experiment to Examine the Possible Existence of Remote Action Effects in Piezoelectric Strain Gauges.” Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 assumed to exist.* As a consequence, we have surveyed the literature for examples of nonstatistical effects for which the experimental protocol also appeared sufficiently rigorous to justify further study. The experiment we are reporting is an extension of earlier work by J. Isaacs.t In our review of published work on RA, his experiments with PZT strain gauges appeared to meet the criteria for attempting replication. In addition, Isaacs claimed to have developed procedures for selecting and training individuals who could produce these effects. In FY 1986, SRI International awarded a subcontract to John F. Kennedy University (JFK), where Isaacs is currently teaching, for the purpose of reproducing the earlier work. During the subcontract negotiations, it was decided that the experiments would be a joint venture, in which SRI designs, engineers and constructs the hardware, and JFK provides the participants. In addition we agreed that a series of trials at the end of the contract year would be carried out at SRI. The rationale for such an arrangement was to make maximum use of expertise at each institution and to protect against conscious or unconscious deception. By using the same participants and hardware at two institutions, effects might be detected at both facilities, thus providing the basis for future “built-in” replication. The FY 1986 program consisted of a screening and preparation phase in order to refine the protocol and select participants, ar: evaluation phase to select the most promising individuals from the screening and preparation phase and a series of trials with those individuals in a study at SRI. * May, E. C., Radin, D., Hubbard, G., Hurnphrey, B., and Utts, J., “Psi Experiments with Random Number Generators: An Informational Model," Proceedings of the 28th Annual Parapsychological Association Convention, Tufts University, Medford, Massachusetts (1985). t Isaacs, J., “A Twelve Session Study of Micro-PKMB Training,” Research in Parapsychology, pp. 31-34 (see Appendix A). Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Tt
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 II METHOD OF APPROACH A. Participant Selection and Training Staff from JFK screened and prepared interested persons to provide participants and protocols for the evaluation phase. The details of the screening, training, and evaluation procedures may be found in Appendix C. In summary, lectures on RA were given to interested groups, followed by a “hands-on” period during which members of the audience were given an opportunity to use portable RA devices (described in Section C1). Individuals showing apparent RA ability were invited to participate further. The JFK staff then began to train participants in RA using a prototype version of the laboratory instrument (described in Section C2) to prepare them for the evaluation portion of the program. The essential elements of the training rely heavily on the concepts of operant conditioning and bio-feedback. Isaacs’ hypothesis is that providing immediate auditory and visual feedback about the state of the PZT sensor can enhance latent RA ability. In addition to training, the following items were defined during the preparatory studies: the RA effect, the thresholds for events of interest, valid data (i.e., circumstances of invalidation), and the analysis and measures of success. Using the final version of the laboratory hardware constructed at SRI for JFK, the participants who successfully completed the first two phases were given further training and evaluation. Those individuals who performed the best were asked to participate in the series of experiments at SRI. B. Hypotheses and Variables In the absence of environmental interference, we postulated that selected participants would be able to modify the normal output of a PZT strain gauge nonstatistically; that is, the signal to noise ratio (SNR) was required to be substantially greater than 1, for an event to be of interest. Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 The independent variable was time. The dependent variable in this experiment was the overall measure of a psychoenergetic effect, as determined from the electrical output of the PZT gauge. The specific criteria were developed during the screening and preparatory phases at JFK and in calibration trials at SRI. From long baseline trials (i.e., 4 to 8 hours for a single trial) with the apparatus, we determined that the system noise was - 4 mV. We decided on an SNR of - 6:1 as the threshold for events of interest and, therefore, set the lower level discriminator at 25 mV. As will be discussed later, the system was always operated in differential mode as a mechanism for rejecting artifact. That is, the absolute value of the voltage difference in the output of the two sensors was defined as the signal of interest. Although, for psychological reasons, the participants were told to focus their attention on only one sensor, the experimenters had agreed to accept any event above the differential threshold. It was, therefore, not critical which sensor the participant actually affected, if any. It was further agreed that the only sessions that would meet the criteria for considering events of interest would be those in which the participant and sensor were located in separate, but adjacent, rooms and in which no invalidating acoustic signals were recorded on the tape-recorder. Three types of controls were employed: (1) The SRI formal phase experiments: environmental monitoring or shielding or both were used. (2) Global controls: extended runs between sessions to rensure long-term system stability. (3) Local controls: data were collected just before or after or before and after an effort session to ensure short-term stability of the system. In future control trials, we will also collect data with an individual in the room whose attention is not focused on the sensors. During the testing and installation of the laboratory instrument, it became clear that it was not possible to test for, to monitor for, or to shield against all possible sources of artifact in the initial series of experiments. Therefore, some potential, but unlikely sources of artifact such as cosmic rays or extremely low-frequency magnetic fields were excluded from immediate consideration. Our goal was to be sufficiently rigorous to determine whether further investigation into this form of RA is justified. The null hypothesis under test was that no events uncorrelated with obvious artifacts would be observed. Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 C. Hardware Construction 1. The Screening Device The purpose of the PK screening device (SD) was to facilitate the selection of subjects exhibiting psychokinetic ability. Shielding against artifact, although of concern, was not the principal design consideration for the SD. In order to allow screening of a large number of subjects, the SD is portable and fairly rugged when packed into two typewriter-size carrying cases. It is quickly and easily assembled on a table or desk top. The SD consists of two parts, a strain gauge sensor and preamplifier assembly and a processing and display unit. The strain gauge sensor and preamplifier assembly are suspended from a stand to provide some degree of mechanical isolation. Miniature coaxial cables connect the sensor assembly to the desktop display unit. The display unit contains the processing and display hardware and the batteries that supply the entire system. The front panel of the display unit has a digital voltmeter (DVM) that displays voltage in millivolts and a twenty-element linear LED bar graph that shows the voltage graphically on a 0- to 2-volt scale. Headphone jacks, volume controls, battery test pushbuttons, and a remote handset jack are located on the right side of the panel. There are three forms of feedback: two visual and one audio. A DVM displays the voltage held by the peak hold circuit of the selected channel, while a twenty-element LED bar display shows the voltage in a bar graph fashion. The selected peak hold output is simultaneously converted to an audio tone that is played into two sets of headphones; one for the subject and one for the operator. Individual volume controls are provided. Once above this threshold, the frequency of the tone increases linearly with the peak held voltage. The two peak holds (signal and control) are reset by a single pushbutton. Both the “reset” and the “channel select” pushbuttons are mounted on a small hand-held cylinder connected to the processing and display unit by a 12-foot cord. The potential participant is told to focus his attention on the suspended strain gauge and by whatever mental strategy seems appropriate, to cause the frequency of the tone to increase and the LED bar graph to rise. More details of construction of these devices may be found in Appendix A. Additional details on their use in the field may be found in Appendix C. Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 2. The Laboratory Apparatus A schematic overview of the laboratory RA apparatus is shown in Figure 1. The actual apparatus may be seen in Figure 2. In designing and constructing this instrument a number of considerations had to be satisfied: (1) Major sources of artifact had to be shielded against and or eliminated through proper engineering. (2) A complex system of graduated auditory and visual feedback was required. (3) Computer printout and outputs for a chart recorder were both needed to provide a permanent data record. (4) The need to adjust almost all session parameters (e.g. threshold, gain, etc.) required that the system be microprocessor based for maximum flexibility. A brief description of each of the system elements is given below. More detail may found in Appendix B. a. Sensor Pair Since it was impossible to anticipate every possible source of artifactual data, we elected to use two PZT sensors operating in differential mode as an additional method of artifact rejection. In this mode, the absolute value of the difference between the output of the two sensors was defined as the signal of interest. An event above threshold would be detected when one of the sensors was perturbed to a greater degree than the other. The intent of this approach was to reject any unshielded transients (e.g., low-frequency magnetic fields, wide area acoustic artifacts, or building movements) that could presumably influence the sensors in a nearly equivalent manner. Each of the two PZT crystals are suspended from a lead mass. Each of the lead masses contains a charge-sensitive preamplifier that drives a fiber-optic link. The PZTs are coated with a silicone insulator to provide electrical insulation and silver paint to provide EMI/RFI shielding. The two PZTs/preamps/drivers are housed in a Hoffman EMI/RFI shielded enclosure of dimensions 20 x 16 x 6 inches. A shielded window (combining wire mesh and a transparent conductive coating) of dimensions 13 x 3 inches was installed so the sensor could be seen: a requirement that the JFK staff believed was psychologically important. Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 i a Ss i‘: mE ec i sg.
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Rechargeable batteries supply the power for all the PZT instrumentation within the shielded enclosure. SENSOR CHART RECORDER ENCLOSURE MICROPROCESSOR CONTROL UNIT PRINTER EXPE RIMENTER’S KEYBOARD VISUAL FEEDBACK UNIT CASSETTE PLAYER (AUDIO) AUDIO FEEDBACK (HEADPHONES) ~ S FIGURE 1 FUNCTIONAL DIAGRAM OF RA APPARATUS Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 LNAWIY3adX4d 1Zd YOd SNLVYWddVY VH 2 SYNOD WALHIANOD G/¥ ' Mee OVeaas4 Olan OL NIT : HOS auVvOgAay SIi1dO Y3aI3 (eqn, 48uul) S3NOHdGV3H any Ey NOILW10S! waunawod ETI (OSE Te) NOILVHSIA —, LYWHO SO CEEEI WS ——— een rn nD anal Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Figures 3 and 4 show the entire sensor system. Details of the construction and engineering are found in Appendix B. b. Signal Processing The STD bus BASIC controller is responsible for all the operator interface, real time clock control, feedback control, and transmittal of data to both printer and TRS Model 102 computer. The data consist of time, voltage from sensor one (V1), voltage from sensor two (V2), and the absolute value of the difference between V1 and V2. These data are fed to two serial ports on the back of the STD controller. One port is connected to the printer, and the other is connected to the TRS Model 102 computer which stores them for future processing. The STD controller also provides chart recorder output for each of the two sensors. The signals from the PZT sensor preamplifier are transmitted to the STD controller via two fiber optic cables. This effectively isolates the battery powered sensor and its circuitry from the line powered STD controller circuitry. The STD controller converts these signals back into voltages. This is accomplished with a fiber optic receiver followed by a frequency to voltage convertor. The signals are then filtered and full wave rectified. The software can select the high pass filter time constant, is either 100 ms or 30 ms. The low pass filter bandwidth is fixed at 1 kHz. After filtering and rectification, the signals are fed to fast attack slow decay circuits. These pulse stretcher circuits have a decay time constant of a few seconds. This is slow enough to allow both subject and operator to “view” the sensor output via the feedback, which is derived directly from the stretched Signals. The chart recorder outputs are derived from the pulse stretchers as well. At this point the two channels are digitized and the remainder of the processing is done in software. A 25-kHz analog-to-digital convertor samples the channels in rapid succession. Because of the long decay time of the pulse stretcher circuits the two channels need not be sampled in a true simultaneous fashion. c. Feedback There are three different modes of operation to drive the feedback: Channel A, Channel B, or differential. Channel A mode uses only the signal from Sensor A to drive the feedback. Channel B mode selects the signal from Sensor B for feedback. Differential mode drives the feedback from the absolute value of |A - B|. Regardless of the feedback Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 TION CHARGE SENSITIVE RD MULTIFUNC EMI GASKETIN( FIGURE 3 SENSOR ENCLOSURE (OPEN) wu “7 wt LL Orn wal a ct to x oO ul c 10 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 _ em tccgoraaniisne maser ne Ceili rl
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 SHIELDED WINDOW SHIELDED ENCLOSURE 2B 2 Sari Ew. Y On Qa ll Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 FIGURE 4 SENSOR ENCLOSURE (CLOSED)
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 mode selected, the data output to the printer and TRS Model 102 computer is as described above. For the purposes of feedback three thresholds are chosen: TO, Ti, or T2 where T1 is greater than TO, and T2 is greater than T1. These threshold values can be selected by the software. These three thresholds divide the signal amplitude into four categories: s< TO, TO<s<T1, Tl <s<T2, ands >T2. For signal values below TO, there is no feedback and no data are generated. For signal values between TO and T1, the audio feedback generated is pink noise of increasing volume. The visual display is not active below T1. For signals between T1 and T2 both the audio and visual feedback become active. The audio feedback is a tone of increasing pitch beginning with middle C and going up an octave. The 8 colored bars of the visual display are illuminated with their respective tones. The update rate for the feedback is such that the decaying signal can be clearly seen and heard as a series of tones with decreasing pitch. Signals with an amplitude above T2 activate a cassette tape recorder and play a tape selected by the subject. The cassette will remain on for a preselected period during which time all signals from the sensors are ignored. 3. Experimental Protocol a. Session Procedure (Typical) Figure 5, shown below, displays the physical arrangement used during the RA experimental series at SRI. The only variations from this layout were during the first 12 sessions when the sensor box was located in the same room as the participant. The final eight sessions were conducted as shown in Figure 5. A typical RA session lasted approximately 90 minutes. The sequence of events is shown below: e Before the JFK experimenter/participant team arrived, the SRI session monitor checked the equiproent for correct functioning and, where scheduling permitted, collected control data just before the participant. arrived. e The period of the experiment comprised three trial periods of approximately 20 minutes and two rest periods of 10 to 15 minutes each. Rest periods were generally taken outside of the immediate area. The participant’s instructions were always to attempt to affect only the left sensor. ° Following the experimental period, the SRI monitor again checked the equipment for proper functioning and, if scheduling permitted, collected more control data before the next session. 12 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 During the experimental session, the tasks of the SRI monitor were as follows: e All session record-keeping, such as time, conditions, personnel, and the like were entered into a laboratory notebook. e An audio, cassette tape-recorder with two microphones was employed to monitor the last 11 sessions for possible acoustic artifactual sources of signals. Recording was begun at the start of the first trial and continued through through the end of the session. The only gap in the record was the few seconds necessary to turn over the cassette. e The monitor observed closely all aspects of the session, ensuring that the JFK team was always accompanied during the breaks and that all experimental rooms were locked when unattended. b. Session Condition and Options The history of parapsychology is replete with examples of conscious and unconscious deception, particularly when large-scale effects have been claimed (e.g., macro-RA). For this reason, the principal duty of the SRI monitor was to ensure that there were no substantive deviations from the agreed-upon protocol while simultaneously preserving an atmosphere of friendliness and encouragement. This requirement was met in part by allowing the participants to interact with the system at three levels of increasing rigor. Those three conditions are listed and discussed below. Only data collected under Condition [II were considered to be of interest. e Condition I--Sensors in the same room with the participant, door to the sensor enclosure open. There is no question that artifactual events are easily produced in this condition. However a key feature of the JFK approach to training RA ability is to build confidence by starting the participant with the most sensitive feedback condition possible and then by gradually introducing more restrictions. Because moving from the JFK to the SRI facility was a dramatic change in psychological setting, a few participants used this condition once as a “warm-up.” Obviously data from this condition were not considered. 13 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 RA APPARATUS OUBLE PANE WINDOW SENSOR BOX tL FIBER OPTICS CABLE RECORDER FIGURE 5 SCHEMATIC OF EXPERIMENTAL AREA FOR PZT RA. The experimenter is designated by “E,” the participant by “P,” and the session rnonitor by “M.” Microphones are located at Positions 1 and 2. Ambient noise was recorded by the microphones at Position 2, audible noise or body movement by the participant was recorded by the midrophone at Position 1. e Condition [I--Sensors in the same room as the participant with the enclosure sealed. This condition was artifact free as long as the individuals were silent and relatively still. Although in principle one could monitor sound and motion artifact induction through appropriate video-tape recording, it was believed that such a procedure would be invasive and probably inhibitory. Because it is impossible for any human monitor to observe all possible activities of the individuals in the room, 14 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 events over threshold in Condition II were discussed. e Condition I1I--Sensors located in a temperature controlled computer room adjacent to the participant’s room, enclosure sealed. The sensor enclosure was still visible through a double-pane glass window especially constructed for this purpose (cf Figure 5), a feature considered by JFK to be psychologically necessary. Considerable noise and movement could now be tolerated in the participant’s area without triggering an event over threshold. However, the SRI staff felt that possible effects of combined mechanical and acoustical resonances were not well understood. As a consequence, any audio signal on the tape-recorders correlated with an RA event invalidated that data. The presence of such Signals invalidated several events collected in Condition III for Subject 034. None of the other 4 participants produced any events in Condition III trial sessions even though 2 of them generated noises. Again, we wish to reiterate our null hypothesis. Based on our testing of the instrumentation during Condition III, we hypothesized that no candidate events would be produced in Condition III that were not rejected by our instrumentation or invalidated by our audio recording. The presence of any residual events would not be considered as evidence for RA but rather as motivation for continued experimentation. 15 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
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Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 As is obvious from Table 1, the number of sessions was not equally distributed across participants. The experimental time was heavily weighted in favor of Subject 032, who was the best participant in the preliminary trials at JFK and ultimately produced the only candidate events at SRI. Because we were seeking evidence that would support the existence of an effect we consider that we are quite justified in our division of experimental time. Should the effect continue to be observed we will of course design the experiments that have balanced conditions across subjects. Figure 6 displays the computer printout from one of the two sessions with Participant 032 in which valid events were detected. The events of interest, which occurred in the first and third trials, are time stamped. No events occurred during the rest periods. The events are printed in the following order; left sensor output, right sensor output, absolute value of the difference. (The following letter “R” has no meaning and may be ignored.) The units in which the data are printed are computer ADC conversion units. To get millivolts, multiply by 2.5. Thus, the first event in Figure 6 is equal to 30 mV, (12 x 2.5). As mentioned earlier, the instructions to the participant were to attempt to affect the left sensor only. That this was the actual outcome is of interest although the absolute value of the difference was defined as the threshold, and therefore, either sensor could have been selectively affected to meet the event criteria. It should be pointed out that the candidate signals occurred in clusters of 4, 4 and 3 events, respectively. In each group, the signals all appeared within 1 to 2 seconds. Therefore, the most conservative evaluation would be to say that there were 3 events rather than 11. During any subsequent experiments, we will record the above threshold voltage as a function of a shorter time scale (e.g., milliseconds) in order to more clearly identify events of interest. During the early sessions, it was found that the chart recorder created a substantial amount of background noise, which was distracting to the participants. It had been agreed that only that data that were above the threshold as processed by the computer ADC would count as an event of interest. We therefore elected to disconnect the chart recorder for this initial series of trials to minimize the environmental distractions and reduce another source of potential acoustic artifact. Using the charge output equations supplied by the PZT manufacturer, we have calculated the amount of energy necessary to produce an event of 30 mV from the PZT 18 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 GO)H GMC please please please ?Redo ° GO)H GO)H END OF GO)H 60O)C please please please ?Redo ” GO)M GOQ)H 6GOC please please please ?Redo ? GO) H GO) M 1@ 1@ 18 10 347 347 2:47 247 :39 13 :490 13 342 12 7:42 11 enter subject's name (up to enter experimentor'’s name enter the session number 1°12 R 1 i2R UTRIAL 1 111 R CANDIDATE EVENTS @ 11 =R 22 characters) : REST 1 (up to 28 characters) 3 SESSION TRIAL 2 NO EVENTS enter subject's name (up to 2 characters) s REST 2 enter experimentor’s name (up to 22 characters) ¢ enter enter enter erter OCTOBER, 1986, the session number subject's name experimentor’s name the session number 11 11 11 149 2349 249 824 13 2 11 R 824 te @ 12 R 225 13112 Rf FIGURE 6 (up to 2@ characters) : TRIAL 3 (up to 28 characters) TRIAL 3 CANDIDATE EVENTS 10:38 A.M., PARTICIPANT: 032 19 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 (including, of course amplifier gains). Such an event would require about 1.4 x 10-18 joules, or around 900 eV. If the source of this energy were radiation, that would correspond to a low energy x—ray. B. Control Trials During control trials conducted after the first few experimental sessions, a building resonance that triggered events over threshold was discovered. This resonance could be excited by personnel walking in a specific area of the hallway. By additional vibration isolation (a partially inflated inner tube) between the sensor enclosure and its floor stand, this source of artifact was eliminated. For the balance of the experimental series, control trials of up to six hours in length were recorded with no one present in the experimental room but with normal activity in the rest of the building. No uncorrelated events above threshold equivalent to those detected in the experimental trials were detected in those control periods. A typical example of the chart record obtained during these control periods is shown in Figure 7. Note that the left sensor is somewhat noisier than the right. This extra noise probably results from small differences in the electrical contacts between the preamps and sensors. However, this small difference should not be significant because the threshold is set a factor of six above the noise of the left sensor. Certainly in any future hardware development we will attempt to further reduce contact noise. C. Possible Sources Of Experimental Artifact The sensor must be isolated from mechanical vibration conducted to it from the surrounding structures. Second, the sensor must be shielded from acoustic vibrations transmitted through the air. Third, thermal influences resulting from either conducted, convected, or radiated heat must be removed. Finally, because the signal of interest is an electrical charge, any external influence caused by electric or magnetic fields must be isolated. 1. Mechanical Vibration The sensor is in a laboratory environment, coexisting with many humans and equipment such as elevators, motor-driven machinery, vehicles, and the like. The building is in an urban area in which large truck and train traffic, as well as aircraft, pass nearby. Because considerable motion vibration exists in the floor of the room in which the sensor is located, the sensor had to be isolated. 20 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Parcs seen f feelers iteetst rt itn oltre se] Rie iegeee ts Saher terre Severn Bape ere ea ee
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Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 The first level of isolation is the sensor enclosure shock mounts. These mounts consist of four commercial elastomeric pads. The enclosure weighs about 100 lbs, including the internal batteries. Weight per mount, resonant frequency, spring rate, static deflection, and isolation efficiency entered into the selection. The enclosure/mount resonance frequency is no more than 10 Hz to ensure reasonable isolation of rotating machinery components at 30 Hz. The next level of isolation is the sensor suspension system, which is a spring—mass type with a much lower resonance frequency than the enclosure. The sensor is attached to a bob weight that is suspended from the top of the enclosure via a spring. The weight is about 2 Ibs; the spring rate was selected to provide a resonance frequency of about 2 Hz. This provides an additional isolation factor of about 12 dB (6 dB/octave) at the enclosure resonance frequency assumed to be about 10 Hz. Beyond 10 Hz, the overall isolation is the sum of the two (12 dB/octave). Extension springs are not characterized for torsional spring rate; however, a check of nearly identical size torsion and extension springs does yield an estimate. For the metallic spring selected above, the torsional spring constant is about 0.1 Ib-ft/radian. Assuming that the sensor weight is a 2-Ib lead sphere, the rotational moment of inertia is about 1.0 x 10-4 lb-ft-sec?, which implies that the rotational harmonic frequency is around 5 Hz. Isolation from low-frequency vibrations (such as those induced by footsteps and vehicle road “rumble”) is not easy to provide. In this case, the assumption is that the energy below 10 Hz (the electrical signal lower frequency cutoff point) will not be so large that it masks the noise that will be visible above 10 Hz. As mentioned earlier an extra vibration isolation element was added to eliminate some specific ambient artifacts. 2. Acoustic Vibration Just as for mechanical vibration, acoustic energy can easily cause the PZT sensor to produce noise signals if the sounds are allowed to impinge upon the PZT element directly. Since this is the case, it would seem obvious that the PZT sensors should be heavily isolated, perhaps by being encased in lead or other sound deadening material. This approach could not be followed since it was considered a necessity that the participant be in visual contact with the sensors. 22 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 As the participants gain confidence in interacting with the apparatus, it is contemplated that more restrictions can be introduced. For the present experiment however, we believe that we were successful in controlling acoustic artifact through the following steps: e Isolation of the sensors in a hard, steel enclosure that reflects higher frequency sounds. e Isolation of the entire sensor enclosure in another room (Condition III). ‘@ Tape recording of all Condition Il sessions. The final step of rejecting any acoustic correlated events was added as a measure of extra caution. Qualitative experimentation demonstrated that, in Condition III, a substantial amount of noise and movement was required to trigger an artifact from inside the participant’s room. However, we could not quantitatively measure the audible sound pressure level and frequencies necessary to generate an artifact at the time of the experiment. Consequently, the use of the tape recorder to reject any events correlated with room noise appeared an appropriately conservative measure. A small amount of conformal coat elastomeric rubber was also applied as a sound—absorbing skin. In addition, the external silver-paint coat (which serves for EMI protection) serves in a small way as an acoustic reflector at the highest frequencies. Proof of the efficacy of all these measures may be found in the control trials and testing. During the course of the testing, we duplicated all the normal ambient noises occurring outside the room (i.e., doors slamming, people talking, etc.). None of these was correlated with any artifact production. 3. Heat-Induced Variations All of the elements that make up the analog portion of the sensor hardware are sensitive to heat in various ways. The sensor is the most critical because its physical size (mass) is very small, which means that the thermal time constant is low also. Hence, any thermal input such as an infrared ”pulse” (from the subject’s hand moving past the viewing window) may induce a response in the sensor if the pulse has significant spectral energy above the system high-pass filter response of 10 Hz. Because IR is long-wave energy, it penetrates many materials and is difficult to shield. The only direct protection is the silver paint applied to the outside of the sensor over the rubber coating. However, the shielded window of the enclosure is covered by an 23 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 anti-reflective coating that reduces the IR transmission. A test of waving one’s hand in front of the sealed enclosure does not produce any IR artifact. Further IR isolation was provided by the isolation of participant and sensor in Condition III (see Figure 5). 4. Electro—-Magnetic Isolation Because the entire sensor system is electronic, it must be shielded from both electric and magnetic field influences. No high-voltage or large-current devices are near the sensor enclosure, and all electrical devices within 100 feet meet the FCC minimum requirements for RFI emission suppression. The primary danger from stray fields (field-to-cable coupling outside our shielded enclosure) is eliminated entirely by using fiber optics cables to carry the signal to the external hardware. The primary shield against EM signals which might affect the PZTs is the basic sensor enclosure, which is a standard industrial NEMA 12 steel RFI-specified box. According to the manufacturer’s data book, this box provides up to 95 dB of magnetic-field shielding from 14 kHz up to 1 MHz, and over 100 dB of shielding for electric fields from 14 kHz up to at least 450 MHz. These levels of performance are degraded if any openings are made in the steel case. The viewing window in the front of the box is of a special EMI/RFI material (metallized and containing an embedded metal mesh). The manufacturer’s specification for the shielding effectiveness (SE) for electric fields is about 80 dB up to 10 MHz. The SE for magnetic fields varies from about 10 dB at 100 kHz to about 45 dB at 10 MHz. Clearly, low frequency magnetic fields directly in front of the window could be a problem. However, the PZT is a capacitive element, not resistive and, therefore, should be relatively insensitive to such fields. In future studies, as the participants gain confidence, we should be able to use an unmodified windowless enclosure. Power resides inside the box in the form of chemical batteries, and the only other holes through the shell are two 1/4-inch openings for the fiber-optic cables. A straightforward calculation can demonstrate that signals must be greater than about 10 GHz to propagate through these openings. Because of internally generated EM fields (from the dc to de convertors and the fiber-optic driver electronics), the sensor and preamplifier are totally enclosed within a metallic shield. This shield is a combination of the lead bob weight or the silver—paint coat; neither of which afford any magnetic shielding. Because all interconnect wires are shielded coaxial or multiconductor cables, they are relatively immune to extraneous fields. A single-point common “ground” was used to minimize “ground loop currents” and the 24 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 associated signal noise voltages. The critical low-noise preamplifier is powered from batteries only. 25 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 SESE Ser a a ea aa sate aaznoenl ai 3 rt Nicene
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 IV CONCLUSIONS Five individuals designated by researchers from JFK University have participated in a series of RA experiments conducted at SRI. Each participant was asked to influence one of a pair of piezoelectric strain gauges, operating in differential mode, to produce an event above a predetermined threshold. Altogether, the five participants contributed 20 sessions, each lasting approximately 90 minutes. The last 8 sessions were conducted in Condition II, in which the sensor enclosure was located in a locked room adjacent to the participant’s area. At that point the participant was approximately 3 meters from the sensor pair. Under those conditions, one of the participants produced a total of 11 events above threshold. Those events, the largest of which was 33 mV, were distributed into three separate effort periods over two sessions on different days. Known sources of artifacts (electromagnetic, acoustic, mechanical, and infra-red) were considered and, wherever possible, controlled, minimized, or measured. However, some potential but unlikely sources of artifact such as cosmic rays and low-frequency magnetic fields were excluded from consideration in this initial series of experiments. The preliminary and pilot nature of these sessions cannot be stressed too strongly, especially since all possible sources of artifact have not been excluded. Nonetheless, our conclusion at this time is that sufficient data have been collected to warrant further investigation. Future studies will heavily emphasize further shielding, detection of rare events that may produce artifacts, possible testing of the apparatus against standard EMI specifications such as MIL STD-461b or TEMPEST, and detection of subaudible acoustic artifact production. 27 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
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Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 General Description: The purpose of the RA screening device (SD) is to facilitate selecting the subjects exhibiting RA ability. The individuals selected using the SD are to be subsequently tested and trained using the RA laboratory instrument. Shielding against artifact, although of concern, is not the principal design consideration for the SD. So that a large number of subjects can be easily screened, the SD is portable and fairly rugged when packed into its two typewriter-size carrying cases. It is quickly and easily assembled on a table or desk top. The SD consists of two parts: a strain gauge sensor and preamplifier assembly and a processing and display unit. The strain gauge sensor and preamplifier assembly are suspended from a stand to provide some degree of mechanical isolation. Miniature coaxial cables connect the sensor assembly to the desktop display unit. The display unit contains the processing and display hardware and the batteries that supply the entire system. The front panel of the display unit has a digital volt meter (DVM) that displays voltage in millivolts, and a twenty-element linear LED bar graph that shows the voltage graphically on a 0-to-2-volt scale. Headphone jacks, volume controls, battery test pushbuttons and remote handset jack are located on the right side panel. Strain Gauge Sensor and Preamplifier: The strain gauge sensor is an aluminum strip (3 inches x 3/4 inches x .016 inches) on which two Omega Y series foil strain gauges have been mounted. These strain gauges have a coefficient of thermal expansion matched to aluminum. The gauges are mounted side by side and oriented parallel to the long (3-inch) axis. The aluminum strip is anchored to a shielded aluminum enclosure (1 inch x 3 inches x 5 inches) that houses the preamplifier circuitry. A small coaxial cable connects each of the two gauges to the bridge and preamplifier circuitry located inside the shielded enclosure. These cables were kept short (2 inches) to minimize sensitivity to electromagnetic fields. The two gauges are connected in serial to make up one leg of the bridge. The three other legs are made up of 240-Ohm resistors. The bridge output is ac-coupled to a Burr Brown 31 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 INA-110 instrumentation amplifier. The INA-110 has a common mode rejection (CMR) of 106 dB and is configured for the maximum gain of 500 using precision trimmed internal resistors. In addition to providing gain, the INA-110 converts the differential signal from the bridge to a single ended signal. An additional gain of 100 is applied by a TL064 operational amplifier followed by a unity gain buffer to serve as a line driver. Thus, the sensor preamplifier applies an overall gain of 50,000. At room temperature, the thermal noise of a 240-Q resistor is 2 nVVHz. The noise voltage of the INA-110 is 10 nV Hz. Clearly, the noise voltage of the instrumentation amplifier is a factor of five greater than the thermal noise of the sensor. System tests showed that the noise floor is limited, not by the INA-110 but by the sensor environment (mechanical vibrations and audio noise). A high-pass filter with a 100-msec. time constant, and a low-pass filter with a 0.1-msec time constant preceed the instrumentation amplifier. The high-pass filter rejects artifacts that are caused by differences in expansion coefficients between the aluminum strip and the strain gauge due to variations in room temperature. The low-pass filter rejects noise as well as pulses shorter than 0.1 msec. The resonant frequency of the aluminum strip is approximately 20 Hz. Exciting the sensor strip mechanically with a pulse narrower than 0.1 msec (which is the low-pass filter bandwidth) will produce a response with an envelope at the resonant frequency of the strip or 20 Hz. This is within the bandwidth of the low-pass filter. The circuitry described above is that for the signal channel. There is also a control channel. The control channel is identical to the signal channel with this exception: the two strain gauges are replaced by two 240-Q resistors. Elements of one channel are located in close proximity to those of the other channel so that any signals induced by local electromagnetic (EM) fields disturb each channel equally. The two resistors used in place of the strain gauges are mounted next to the strain gauges on the aluminum strip. Batteries provide the power to drive the sensor circuitry in the processing and display unit. An 8-volt regulator in the sensor enclosure is used to derive the bridge voltage. By connecting the two strain gauges in series, the voltage across them is kept to only 4 volts, well below the 9 volt maximum specified. Processing And Display Unit: The function of the processing and display unit is to take the sensor outputs from the preamplifiers and feed them back to the operator in real time. The amplified signals from the sensor preamplifiers enter the processing and display unit and are again amplified by a factor of three for an overall gain of 150,000. After amplification, the signals are injected into a low-pass filter 660 Hz with a rolloff of 12 dB per octave. To complete the signal processing, a full wave rectification and peak hold are done on each channel. 32 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 St ES _
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 The signal processing functions described above are realized by two identical channels of hardware: one for the signal channel, and one for control. From this point on the hardware is shared between the two channels. The operator chooses the desired channel with a pushbutton toggle switch. There are three forms of feedback: two visual and one audio. A DVM displays the voltage held by the peak hold circuit of the selected channel, while a twenty~element LED bar display shows the voltage in a bar graph fashion. The selected peak hold output is simultaneously converted to an audio tone (using a V to F converter), which is played into two sets of headphones: one for the subject and one for the operator. Individual volume controls are provided. The threshold for the tone can be is adjusted via an internal resistor. Once above this threshold, the frequency of the tone increases linearly with the peak held voltage. The two peak holds (signal and control) are reset by a single pushbutton. Both the “reset” and the “channel select” pushbuttons are mounted on a small hand-held cylinder connected to the processing and display unit by a 12-foot cord. The screening device is powered by three different batteries. A 9-volt alkaline battery with a lifetime of 6 months powers the DVM. The negative 12 is supplied by two 12-volt smoke alarm batteries connected in parallel. These provide 25 hours of continuous operation. A 12-volt 2.6-amp hour rechargeable gel cell supplies the +12 and +5 volts. A fully charged battery will provide 10 to 20 hours of operation depending on LED usage. A battery test pushbutton and a battery select switch (+12 or -12 volt) display the selected battery voltage on the front panel DVM. The DVM is equipped with a “low battery” indicator for the 9—-volt alkaline cell that powers it. Performance: Testing in the Geoscience And Engineering Center demonstrated that with the high degree of sensitivity built into the electronics, noise tended to be a problem. By reducing the low pass filter bandwith to 660 Hz, thermal noise at the output is theoretically reduced to 200 mV. With a 2-volt full-scale voltage, this poses some obvious problems. Fortunately because random thermal noise will be present on both channels, the control channel can provide a baseline to which the signal channel may be compared. With the SD on a table in our laboratory, which is not a particularly quiet environment readings as high as 300 mV were recorded. We believe these signals were produced by the ventillation system and ambient noise. Aside from thermal noise, there is of course mechanical vibration of the table on which the sensor stand rests as well as acoustic noise. The sensitivity of the screening device is such that air currents, particularly those normal to the aluminum strip surface, produce measurable strain. These effects can be minimized by training the operators prior to subject testing. 33 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 The effect of electromagnetic fields on the screening device proves to be minimal. Keeping the connections between the gauges and preamplifiers short, the use of coaxial cable, and shielding the sensor circuitry in its enclosure, together provide good electromagnetic isolation. 34 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 ‘2s al ART Teale aan timated leit. te |
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 Background The requirement for an RA phenomena measurement and for the monitor set has been established, and most functional and some aspects for form and fit have been delineated. This technical note describes the design details of the sensor section of the instrument. Sensor Type The sensor is a version of the standard commercial PZT ceramic element offered by several manufacturers in a variety of shapes, sizes, and configurations for applications ranging from high-voltage generators to low-level sound pickups. The sensor is a Piezoelectric Products R1i01S, with dimensions 1 x 0.125 x 0.005 inches. This PZT is designed to produce an electric charge when it is flexed laterally and so it is assumed that such motion (or its equivalent) is the mechanism by which the RA agent influences it. Mounting the element is therefore in keeping with that mode of physical motion. The mechano electrical characteristics are given in the data sheets; the salient parameters are. ® Electric Charge output vs. force F (free-flexure mode) (0.18 x 10-8) x (L)? pC/N e Electric Charge output vs. deflection z, 23/L pC/mm, where L is the node-to-node beam length in mm. The free-flexure mode assumes a fundamental symmetrical flexing about two nodes near the free ends. The driving force is considered to be applied at the center of the “beam.” The applied force F is in newtons, whereas the deflection z is in millimeters. As can be seen, the output charge is very small, especially when one calculates the allowable deflection z to remain in the safe linear operating range. For example, using an element 10 mm long (L), 1 = 5.5 mm and the center deflection z must be limited to a small fraction (< 0.01) of that length. Thus, the largest charge from the element is about 0.04 micro pC. 37 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 The minimum charge (hence deflection) is dependent upon the noise contribution of the amplifier used to bring the signal response up to a usable level. The sensor has natural fundamental and harmonic resonance frequencies that can be calculated once the physical dimensions are known. Again, using the size numbers from the preceding paragraph, a typical fundamental nodal-support frequency is around 85 kHz. However, it is of no importance to the present application because the expected RA source driving function “duration” (at least the observed one) is in the range of a few milliseconds to a few tens of milliseconds. Thus, the sensor appears as a virtual flat-amplitude charge generator with respect to the frequency bands of interest (10 Hz to 1 kHz). Signal Amplification Because the sensor is a charge generator that has essentially a pure capacitive source impedance (well below resonance), the most appropriate signal amplifier is an operational amplifier configured as a charge amplifier. The feedback elements were chosen to effect both the low- and high-pass filter corner (-3 dB) frequencies of 1 kHz and 10 Hz, respectively. Because the charge quantities involved are very small, the amplifier input bias and noise currents are as small as possible. Again, because there was no specification as to the level of the RA-induced deflection that could be expected, the approach was to choose the very best low-noise operational amplifier available and calculate the minimum equivalent deflection “noise.” The equation for a charge amplifier using a 10 pF feedback capacitor yields a transfer gain of 0.1 V/pc. Assuming a 1000 pF coupling capacitor and a 20 M-Q bias feedback resistor, we obtain a high-pass filter corner frequency of 8 Hz and a low-pass filter corner frequency of 800 Hz. The configuration yields unity voltage gain and a current transfer gain of 20 V/pA. A high-quality, low-noise, low-bias—current operational amplifier has an equivalent input noise voltage of a few microvolts rms. Hence, the output noise voltage will be the same (unity voltage gain). However, the output noise voltage due to the input noise current can be larger depending upon the value of the feedback resistor. An achievable value for the noise current of 30 fA for the 0.3-to-10-Hz band and 100 fA for the 10-Hz~-to-10-kHz band implies that the output noise voltage will be about 2 uV. In this case, the noise contribution due to the input noise current is about the same order of magnitude as the contribution from the input noise voltage. 38 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6
Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6 In any case, the equivalent noise voltage is less than about 5 pV rms, which established the sensor/amplifier sensitivity limit. Using the transfer gain value of 0.1 V/pC, the charge sensitivity is then 50 x 10-18 C rms. Using a detection noise threshold of 14 dB minimum, the minimum detectable charge is 250 x 10-18 C. Because the flexure-mode PZT element has a mechano electrical transfer constant of about 4 »C/mm, the equivalent motion for a minimum detectable signal is about 6 x 10-4 meters. A more useful interpretation is that the electronic noise is orders of magnitude smaller than the environmental noise from the PZT sensor. Environment Isolation As explained in the previous paragraphs, the sensor/amplifier combination allows for measuring extremely small mechanical motion. Concommitant, it is clear that for RA measurements, unless the ambient physical environmental effects are excluded from the sensor, performance is compromised. First, and foremost, the sensor must be isolated from mechanical vibration conducted to it from the surrounding structures. Second, it must be shielded from acoustic vibrations transmitted through the air. Third, thermal influences resulting from either conducted, convected, or radiated heat must be removed. Finally, because the signal of interest is an electrical charge, it must be isolated from any external influence due to either electric or magnetic fields. Mechanical Vibration The sensor is in a laboratory environment, in which there are with many humans and and pieces of equipment such as elevators, motor-driven machinery, vehicles, and the like. The building is in an urban area in which trucks and trains, as well as aircraft, pass nearby. Considerable motion fromo mechanical vibration exists in the floor of the room where the sensor is located; those motions had to be isolated. The first level of isolation is to shock-mount the sensor enclosure of commercial elastomeric pads. The enclosure weighs about 100 Ibs, including the internal batteries. Weight per mount, resonant frequency, spring rate, static deflection, and isolation efficiency entered into the selection. The enclosure/mount resonance frequency is no more than 10 Hz to ensure reasonable isolation of rotating machinery components at 30 Hz. 39 Approved For Release 2001/03/07 : CIA-RDP96-00789R002200100001-6