GB817759A - Improvements relating to radiation monitoring devices - Google Patents
Improvements relating to radiation monitoring devicesInfo
- Publication number
- GB817759A GB817759A GB1525455A GB1525455A GB817759A GB 817759 A GB817759 A GB 817759A GB 1525455 A GB1525455 A GB 1525455A GB 1525455 A GB1525455 A GB 1525455A GB 817759 A GB817759 A GB 817759A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve
- grid
- potential
- frequency
- chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000000903 blocking Effects 0.000 abstract 1
- 230000001186 cumulative Effects 0.000 abstract 1
- 238000009877 rendering Methods 0.000 abstract 1
- 238000004804 winding Methods 0.000 abstract 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/02—Dosimeters
- G01T1/14—Electrostatic dosimeters
Abstract
817,759. Transistor circuits; pulse generating circuits. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. May 28, 1956 [May 26, 1955], No. 15254/55. Class 40 (6). [Also in Group XL (b)] A device for determining when an accumulated dose of radiation has reached a predetermined level consists of an ionisation chamber IC coupled to a valve V1 controlling the frequency of oscillation of an audio oscillator TR1. The chamber IC is connected to the grid of the valve V1 and is given an initial charge by the application of a potential to terminals a+ and a -. These terminals are subsequently connected together thus rendering V1 non-conductive. Junction transistor TR1 is arranged to form a blocking oscillator and with V1 non-conductive operates at a very low frequency to produce an audible clicking in the earphone P connected to transformer winding L3. When sufficient radiation has fallen on chamber IC to discharge it to a point when V1 conducts bias current flows in the transistor base circuit causing an increased audio-frequency tone to be heard. To speed up the change from the non-conductive to the conductive state of valve V1 an additional transistor TR2 is provided. This is normally biased almost to cut-off and the screen grid of V1 is thus at a low potential. Commencement of anode current flow for V1 lowers the base potential of TR2 increasing the current flowing in R3 and so raising the screen-grid potential of V1. The action is cumulative and results in a sharp change in audio frequency. In an alternative circuit (Fig. 2, not shown) V1 is replaced by a tetrode valve and the inner electrode of the chamber is connected to the valve's second grid. The collector of TR2 is connected to the valve grid and R3 is omitted. In this embodiment the grid and cathode of the valve form a diode which, when it conducts, alters the oscillator frequency. If it is desired to measure the residual voltage across the chamber at any time an adjustable calibrated source of potential may be connected across the terminals a+ and a - and the potential required to initiate a frequency change in the indicator circuit determined.
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB817759A true GB817759A (en) | 1959-08-06 |
Family
ID=1731379
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1525455A Expired GB817759A (en) | 1955-05-26 | Improvements relating to radiation monitoring devices |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB817759A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1179308B (en) * | 1960-07-15 | 1964-10-08 | Graetz Kommanditgesellschaft | Electrical radiation warning device |
-
1955
- 1955-05-26 GB GB1525455A patent/GB817759A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1179308B (en) * | 1960-07-15 | 1964-10-08 | Graetz Kommanditgesellschaft | Electrical radiation warning device |
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