GB2385935A

GB2385935A - Radiation detecting probe and test rig

Info

Publication number: GB2385935A
Application number: GB0300818A
Authority: GB
Inventors: Lance Harold Rayner
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-01-15
Filing date: 2003-01-15
Publication date: 2003-09-03
Also published as: GB0300818D0; GB0200775D0

Abstract

A probe, for detecting high-frequency electromagnetic radiation of the type emitted by a mobile telephone, where the probe (10) comprises: an aerial system (12), adapted for receiving the relevant radiation; a rectifying and amplifying circuit operatively connected to the aerial and providing an output representative of any relevant signal picked up by the aerial; output means (14) whereby the thus-rectified and amplified output can be supplied to a warning device able to provide an indication that relevant radiation has been received; and a container body within which the circuit is retained, and from one end of which projects the aerial (12). Also disclosed (see Figure 4) is a test rig for simulating the use of a mobile or like apparatus being an emitter of high-frequency radiation adjacent the human head. The rig utilises the aforementioned probe, the rig comprising: a first stand (47) to which may be detachably secured the emitter apparatus to be tested; a plate (46) or other surface representing the human skull and associated flesh and positioned with its obverse surface immediately adjacent the emitter stand; and a second stand (48) to which may be detachably secured the probe (10) positioned immediately adjacent the reverse surface of the skull-representing plate with its aerial (12) appropriately aligned with the emitter apparatus; the rig also including warning means (49) to which the probe's output can be supplied to provide an indication that relevant radiation has been received.

Description

Radiation detector This invention is concerned with a radiation detector, and relates more specifically to a device for the detection and measurement of the radiation emitted by mobile telephones.

There is presently some considerable anxiety about whether the high frequency electromagnetic radiation emitted by mobile telephones- "mobiles"-is harmful to the User. After all, having an emitter of even weak EM radiation clamped to a User's ear, a mere few inches/centimetres from the User's brain, seems unlikely to be of benefit, and-bearing in mind what other forms of EM radiation are known to docould well be detrimental, causing significant, albeit small and localised, physiological damage to the User. To put figures to this, it is generally the case that contemporary mobiles emit pulsed radiation at a frequency of around 900MHz and an average power level in the range 0.2 to ImW (the pulsing permits the implementation of time division multiple access), and that around 60% of the emitted radiation is absorbed by the User's brain.

Now, though not in the same league as the 2.45GHz output by microwave ovens, the 0,9GHz of a mobile is likely to cause significant heating of the User's brain, and may well result in additional subtle biological changes, not directly associated with such heating. These changes could include: genetic damage, possibly resulting in an increased risk of tumours and cancer; reduced blood-brain barrier selectivity, resulting in increased toxin sensitivity and neurone damage and premature aging; de-myelination of nerve sheaths; and nerve cell synaptic transmission modification, manifested as memory loss, fatigue and disturbed neurone response. Pulsed radiation emitting'phones seem likely to be more damaging than non-pulsed, for during pulse emission peak power output may be as high as lOW, well about the stipulated safe levels.

The interest in the radiation output by mobiles-and, indeed, other electrical equipment used in close proximity to the human body, such as small portable computers-has resulted in much work of devices for detecting and measuring that output, as well as devices for protecting the User from that output. The present invention concerns the former type, and relates in particular to portable, hand-held detectors for such radiation, and also to apparatus using such detectors in a way that mimics the physical arrangement in which they are used adjacent the human head and brain.

In one aspect, therefore, this invention provides a probe, being apparatus for detecting high-frequency electromagnetic radiation of the type emitted by a mobile telephone, the probe comprising: an aerial system, adapted for receiving the relevant radiation; a rectifying and amplifying circuit operatively connected to the aerial and providing an output representative of any relevant signal picked up by the aerial; output means whereby the thus-rectified and amplified output can be supplied to a warning device able to provide an indication that relevant radiation has been received; and a container body within which the aforesaid circuit is retained, and from one end of which projects the aerial.

The probe of the invention is primarily for use as apparatus for detecting high-frequency electromagnetic radiation of the type emitted by a mobile telephone, though it can be employed with other types of equipment, such as hand-held computers, tape-and CD-players, and the like.

The invention's probe includes an aerial system adapted for receiving the relevant radiation. The aerial system conveniently has both an elongate tubular probe section-a tube of, say, brass-and a large area flat section.

Within practical limits the longer the aerial's probe section is the betterthe more radiation it picks up. The probe section may be fully retractable (so it can be stored away out of harm's way), or alternatively it can be flexible, so as to bend out of the way.

The aerial system includes as a component a large area flat section forming a radiation-gathering member. A typical such section is a simple copper or brass plate.

The probe of the invention incorporates a rectifying and amplifying circuit operatively connected to the aerial and providing an output representative of any relevant signal picked up by the aerial. Although such a circuit could be active, and powered (by a small battery, say) it will usually be sufficient if it is like an old-fashioned crystal set, and made of a rectifying diode feeding a tuned RC circuit.

Preferably the circuitry is mounted against a conductive surface forming a radiation shield. This reduces the chances of spurious signals being picked up and confusing the results. A typical shield is a simple copper or brass plate.

The circuit in the probe has output means whereby the thus-rectified and amplified output can be supplied to a warning device-typically a measuring meter (a conventional multimeter is suitable)-able to provide an indication that relevant radiation has been received. A typical such output means is merely a pair of wires with appropriate connectors at the end.

The probe has a (elongate) body within which is contained the aforesaid circuit and its shield, and from one end of which projects the aerial.

Preferably, from the other end of the body there projects a handle by which the probe can be held. The handle is conveniently a simple"rod", shaped to fit comfortably in the hand, much as is used on the end of a hair brush or poker.

The probe's circuit outputs a signal to a warning device such as a meter. This device can, of course, be quite separate from the probe's body, or it can be built in to the body.

In a second aspect the invention provides a test rig for simulating the use of a mobile or like apparatus being an emitter of high-frequency radiation adjacent the human head, which rig utilises the aforementioned probe, the rig comprising: a base upon which the following components of the rig are mounted; a first stand to which may be detachably secured the emitter apparatus to be tested; a plate or other surface representing the human skull and associated flesh and positioned with its obverse surface immediately adjacent the emitter stand; and a second stand to which may be detachably secured the probe positioned immediately adjacent the reverse surface of the skull-representing plate with its aerial appropriately aligned with the emitter apparatus; the rig also including warning means to which the probe's output can be supplied to provide an indication that relevant radiation has been received.

As will be clear, the invention's test rig is in essence the combination of a stand for the mobile) or the like), a stand for the probe, and between them a skull-like plate through which the mobile's radiation has to pass to reach the probe. This is intended to be like a mobile clamped to a User's ear, with the probe somewhere in the brain!

Preferably the probe is one in which the circuitry is mounted upon a shield, and the probe is positioned on the second stand with its shield facing the reverse surface of the skull-representing plate.

The rig's components are all mounted upon a base, which can take any appropriate form. It may be convenient, though, if the mounting positions are adjustable, to allow the components to be moved back and forth relative to each other.

The first component is a first stand to which may be detachably secured the emitter apparatus-a'phone, say-to be tested. Any sort of stand will do, though preferably it allows the emitter apparatus to be adjustable thereon, especially for height.

The second component is a plate or other"surface"representing the human skull and associated flesh. This may be of any suitable material; many common plastics, such as polythene, have the right characteristics. The plate has its obverse surface immediately adjacent the emitter stand-so that in use the combination is like a'phone (say) clamped to the User's ear.

The plate can be a simple flat (planar) plate, but may alternatively be shaped into the form of a human head, the probe stand (see below) then being"inside"the head.

The third component is a second stand, to which may be detachably secured the probe. Again, this can be of any sort, and is preferably (height) adjustable, to allow for differently-sized equipment. This second stand is positioned immediately adjacent the reverse surface of the skullrepresenting plate, with its shield facing that surface (to block any spurious signals) and its aerial appropriately aligned with the emitter apparatus.

Where the rig's plate-simulating a User's skull, and separating the two stands-is shaped like a human head then the probe stand is positioned "inside"the head.

The rig also including warning means to which the probe's output can be supplied to provide an indication that relevant radiation has been received. As noted above, the warning device can be of any sort but is typically a measuring meter (a conventional volt meter or multimeter is suitable) to which the probe's output is fed via its output means.

Embodiments of the invention are now described, though by way of illustration only, with reference to the accompanying diagrammatic Drawings in which: Figure 1 shows a perspective view of a probe of the invention; Figure 2 shows a perspective view of the arrangement of the components of the probe of Figure 1 ; Figure 3 shows a circuit diagram of the probe of Figure 1; Figure 4 shows a perspective view of a test rig of the invention using the probe of Figure 1 ; and Figure 5 shows a perspective view of an alternative test rig of the invention using the probe of Figure 1.

Figure 6 shows a view of the radiation pattern of a typical mobile telephone; The probe (generally 10) shown (in different ways) in Figures 1-3 has a container-like body (11) from which projects a brass tube aerial section (12) at one end and a shaped handle (13) at the other. The circuit components of the probe are shown in Figures 2 and 3. They form a rectified RC circuit; the voltage induced in the aerial is half-wave rectified by a diode (Dl) and then passed to a low-pass smoothing circuit composed by the resistor (Rl: 1KQ, 2%) and the parallel combination of three different capacitors (Cl : 220/iF, 6.3v electrolytic; C2: 220pF, ceramic; and C3: 0, 0221. iF, 400v polyester). The output of the circuit is sent on by leads (14) to a suitable warning device-a built-in meter (15). or a separate meter 25 in Figures 4 & 5.

The circuitry (D1, C1, C2, C3) is mounted against brass plate (20) which acts as a radiation shield.

Figures 4 and 5 show two different test rigs of the invention; in each the components are mounted upon a base (40). The rig in Figure 5 uses a plastic representation of a human head (56), with the probe 10 inside it, while that of Figure 4 uses merely a plastic plate (46).

In each Figure there is"outside" (on the right, as shown) the head/plate 56/46 an adjustable stand (generally 47) holding a mobile phone, while "inside" (on the left) there is an adjustable stand (generally 48) holding the probe 10. In each case the probe's output is passed via leads 14 to a meter 49 which indicates the strength of the received signal.

Figure 6 shows a view of the pattern (61) of radiation (R) of a typical mobile telephone (47) while it's in use against a User's ear. It hardly needs additional comment.

Claims

Claims 1. A probe, being apparatus for detecting high-frequency electromagnetic radiation of the type emitted by a mobile telephone, the probe comprising: an aerial system, adapted for receiving the relevant radiation; a rectifying and amplifying circuit operatively connected to the aerial and providing an output representative of any relevant signal picked up by the aerial; output means whereby the thus-rectified and amplified output can be supplied to a warning device able to provide an indication that relevant radiation has been received; and a container body within which the aforesaid circuit is retained, and from one end of which projects the aerial.
2. A probe according to claim l, in which the aerial system has both an elongate tubular probe section, and a large area flat section.
3. A probe according to claim 2 in which the elongate probe section is extendable, having a storage condition and an extended in use position.
4. A probe according to any one of the preceding claims, in which the circuit is mounted against a conductive surface forming a radiation shield.

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5. A probe according to any one of the preceding claims, in which the probe has a body within which is contained the aforesaid circuit, and from one end of which projects the aerial, and from the other end of which body there projects a handle by which the probe can be held.
6. A test rig for simulating the use of a mobile or like apparatus being an emitter of high-frequency radiation adjacent the human head, which rig utilises a probe according to claim 1, the rig comprising: a first stand to which may be detachably secured the emitter apparatus to be tested; a plate or other surface representing the human skull and associated flesh and positioned with its obverse surface immediately adjacent the emitter stand; and a second stand to which may be detachably secured the probe positioned immediately adjacent the reverse surface of the skull-representing plate with its aerial appropriately aligned with the emitter apparatus; the rig also including warning means to which the probe's output can be supplied to provide an indication that relevant radiation has been received.
7. A test rig according to claim 6, in which the probe is according to claim 4, and the probe is secured to the second stand with its shield facing the reverse surface of the skull-representing plate.

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8. A rig according to claims 6 or 7, in which the components are adjustably mounted upon a base such that the components may be moved back and forth relative to each other.
9. A rig according to any one of claims 6,7 or 8, in which the plate or other"surface"representing the human skull and associated flesh, is polythene.
10. A rig according to any one of claims 6 to 9, in which the plate is shaped into the form of a human head, the probe stand then being "inside"the head.
11. A rig according to any one of claims 6 to 10 in which the second stand is (height) adjustable, to allow for differently sized equipment.
12. A rig according to any one of claims 6 to 11 in which the warning device is a measuring meter to which the probe's output is fed via its output means.
13. A probe being apparatus for detecting high-frequency electromagnetic radiation of the type emitted by a mobile telephone arranged substantially as described herein with reference to and as illustrated in figures 1 to 3 of the accompanying drawings.
14. A test rig for simulating the use of a mobile or like apparatus being an emitted of high-frequency radiation adjacent the human head, arranged substantially as described herein with reference to, and as illustrated in, figures 2 to 4 of the accompanying drawings.

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15. A test rig for simulating the use of a mobile or like apparatus being an emitted of high-frequency radiation adjacent the human head, arranged substantially as described herein with reference to, and as illustrated in, figures 2,3 and 5 of the accompanying drawings.