| 型号 : | FWT-60-00 | 品牌 : | Radiachromic |
| 加工定制 : | 否 |
包装规格：FWT-60-00：1厘米×1厘米×42-52微米，1000片/盒，每盒卖FWT- 60 -20T：10x 10厘米张，每张卖FWT- 60 -20F：15×15厘米，每张卖FWT- 60- 20：45x 15厘米的自定义尺寸，每张卖
FWT-60-1P 1 Dosimeter in Aluminum Pouch FWT-60-2P 2 Dosimeters in Aluminum Pouch FWT-60-3P 3 Dosimeters in Aluminum Pouch FWT-60-1R 1 Dosimeter in small Aluminum Pouch FWT-60-2R 2 Dosimeters in small Aluminum Pouch FWT-60-00 FWT 60 20F Radiochromic sheets 15 x 15 cm FWT-60-20T Radiochromic sheets 10 x 10 cm FWT-60-810 Extra thin Radiochromic Dosimeter, FWT-80 FWT-81 FWT-85 FWT-86 FWT-70-40M Opti-Chromic Dosimeter for 0.01 to 1 1-4 sets or 5-9 sets FWT-70-83M kGy 10+sets FWT-87 Opti-Chromic Detector Holder FWT-87C Spare caps for FWT-87 FWT-92D FWT-92D-220 FWT-92H FWT-82 FWT-200 FWT-173 This PAL discusses the use, handling, and calibration of the FWTseries of Radiachromic Dosimeters. It gives general useguidelines as well as a wealth of information gathered over theyears from users and the manufacturers. Most of theinformation needed to use these products is represented here.I. GENERALA. DosimetersThis sheet contains information on the FWT-60 series ofdosimeters. This includes:FWT-60-00 1 cm x 1 cm squareFWT-60-20F 15 cm x 15 cm squareFWT-60-810 8-10 μm thickFWT also manufactures the Opti-Chromic series of dosimetersthat are useful for lower doses than the FWT-60 series.Dose range: 0.5 to 200 kGy; Dose rate independent to 1012 Gy s-1B. ManufacturingThe FWT-60 series of dosimeters are manufactured by Far WestTechnology (FWT) at its factory in Goleta, California, USA. Themanufacturing process involves many steps and is a proprietaryprocess. Each step of manufacturing is closely monitored forquality. Below is a list of the steps used to manufacture thedosimeters.1. Manufacturing the Dye and its components. FWTmanufactures its own dyes that are used in the dosimeters.This insures that the dye is of high purity and quality. Thenylon matrix that holds the dye goes through severalconditioning steps. Clear, blemish free dosimeters are theresult of the extra steps in the manufacturing procedures.2. Solvent casting large sheets of dosimeters.Dye/nylon/solvent solutions are evenly spread overextremely flat sheets of glass. The solvents evaporateleaving a free standing film which is then peeled from theglass. The goal in casting the dosimeters is an eventhickness which is best performed by casting thedosimeters in sheets. No other form of manufacturing hasbeen found that results in consistent even thicknessdosimeters.3. Drying and aging the sheets. The sheets are not completelydry after peeling. They are hung in cabinets with acontinuous airflow for 3 months to finish the drying/curingprocess.4. Cutting the sheets into proper dosimeter size. The sheetsare then cut into the required size. They are usually cutinto 1 cm x 1 cm squares for the FWT-60-00 dosimeters.5. Inspecting and sorting each dosimeter. Each FWT-60-00dosimeter is visually checked and sorted by thickness. Thethickness of the dosimeters is measured by very sensitiveinstruments capable of measuring to 0.0001 mm.6. Pouching and packing the dosimeters. Some dosimeters areboxed in quantities of 1000. Others are put into foilpouches, hermetically sealed and then boxed.Of course shipping is an additional step that is handled by ourshipping department.C. Chemical CompositionThe FWT 60 dosimeters are composed of hexa(hydroxyethyl)pararosaniline nitrile. The matrix that holds the dye is nylon.The film has a density of approximately 1.15 g/cm3 and acomposition (by mass) of 63.7% C, 12.0% N, 9.5% H and 14.8% O.D. Dosimeter lot numberingThe lot numbers are four digit numbers that are sequentialaccording to product production run numbers, thus film lots willnot necessarily have consecutive numbers. There is usually onlyone lot per year and each number is unique.II. HANDLING THE DOSIMETERSA. Physical handlingThe dosimeters are strong soft nylon films. They can be handledby picking them up with your fingers, but this can be difficultbecause they are so thin. Picking them up this way will leavefingerprints which can change the optical density readings andthus the exposure data. For these reasons we suggest that youhandle the dosimeters with round tipped tweezers, the tweezerswe use.USING RADIACHROMIC DOSIMETERS PAL-1PAL 1 USING RADIACHROMIC DOSIMETERS PAGE 2 OF 7B. Ambient lightThe dosimeters will change color from penetrating radiation andfrom UV light below 370 nm. Most artificial lights contain somelight in this region and will cause a color change in thedosimeters exposed to the light for very long. Sunlight of coursecontains a large quantity of UV–even sunlight through a windowwill contain enough UV to quickly alter the color of a dosimeter.For this reason, we recommend a complete survey of the areawhere the dosimeters will be exposed to all forms of light. Ifthe area uses fluorescent lights or has some daylight, then thearea will probably need filters.A simple test for UV exposure is to place several uncovereddosimeters of known optical density in the area wheredosimeters will be used. Leave the dosimeter in the work area,exposed to ambient light, for 8 hours. If the density changewith the exposure is greater than 0.005 OD then the area needsto be filtered. You may want to filter it even if the test showsnegative since accidental stray light can have quite an effect onthe dosimeter reading. For critical measurements werecommend always filtering all light sources. This includeslights on electronic equipment.Filtering can consist of covering fluorescent tubes with filtersleeves, covering windows with UV film, covering light fixtureswith UV film and purchasing UV free products. Filters areavailable for fluorescent tubes, incandescent lamps and forwindows. All of these materials are designed to block UV lightand will do an adequate job of protecting your dosimeters fromexposure.FWT sells both paper envelopes and aluminum laminate pouchesto protect the dosimeters when they are in use duringirradiation. See section C1 and C2 for information on theseproducts.Exposing the dosimeters to visible light for prolonged periods (onthe order of days to weeks) may cause a decrease in sensitivity.This can occur with no change in background OD. For thisreason, we recommend storing the dosimeters in the dark.C. PackagingThe dosimeters should be protected during exposure. Abrasion,UV light and dirt may all affect the final OD reading and thus thecalculated dose. Protecting the dosimeters is as simple asputting them inside an envelope or a pouch. Envelopes protectthe dosimeter from UV, dirt and abrasion. Pouches also protectthem from humidity change.