| TNT 12000 DoseMate Dosimeter Specifications |
| Accuracy |
| Exposure and Exposure Rate Accuracy |
| |
± 1 % of reading ± 2 range resolution steps over range of 18 °C to 28 °C and ± 2 % of reading ± 2 range resolution steps over the full operating temperature range of 0 °C to 50 °C |
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3 % NIST-traceable calibration is provided with each system and includes effects of 96035B, and 96020C |
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| Measurement Modes |
| Dose |
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Autoranging across five decades of sensitive ranges |
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Automatic drift and offset compensation |
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Automatic post-exposure display hold |
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| Rate |
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Measurement range covers a span from low-level image intensifier measurements to unattenuated, direct beams |
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Automatic offset compensation and nonlinear filtering |
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Autoranging provides five decades of sensitivity ranges |
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Display updates once per second |
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| Low Rate Mode |
| |
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This mode is only for making very low dose rate measurements. Nonlinear digital filtering and autoranging provide five decades of sensitivity ranges. Display updates once per second. In this mode, automatic current offset and drift compensation are disabled. As a result, the system can display very low dose rates |
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| Power Requirements |
| Bias Voltage Supply |
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Fixed electronic bias (~300 V) |
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Bias voltage removed from triaxial input connector at instrument turnoff |
|
| Connections |
| Ion Chamber Input |
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Triax, BNC |
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Collector and guard positive-biased relative to ion chamber body and service dosimeter chassis |
|
| Power |
|
| General Information |
| Display |
| |
Wireless ZigBee or optional USB interface to TNT 12000 display indicates all ion chamber identification information, numerical measurement results, battery level, calibration date, and other information |
|
| Weight |
|
| Dimensions (maximum) (WxDxH) |
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15.2 cm x 11.4 cm x 4.45 cm |
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(6 in x 4.5 in x 1.75 in) |
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| Technical Specifications |
| Energy Range |
| 96020C |
30 kVp to 150 kVp |
| 96035B |
30 kVp to 150 kVp for diagnostic measurements |
| |
20 kVp to 50 kVp for mammographic measurements |
|
| Nominal Volume |
| 96020C |
150 cm3; 11.30 cm diameter by 1.5 cm thick active volume |
| 96035B |
15 cm3; 3.96 cm diameter by 1.22 cm thick active volume |
|
| Nominal Sensitivity |
| 96020C |
H60: 2.08 R/C x 107 R/C at 22 °C and 760 mmHg (optimized for low-level image intensifier and cine measurements) |
| 96035B |
L100: 2.0 R/C x 108 R/C at 22 °C and 760 mmHg |
|
| MV30 (PTB Mammo Point) |
| 96020C/96035B |
2.21 R/C x 108 R/C at 22 °C and 760 mmHg (flat energy response suitable for conventional diagnostic radiography and mammography) |
|
| Leakage Current |
| 96020C/96035B |
< 10 fA under normal bias conditions (300 V) |
|
| Collection Efficiency |
| 96020C |
95 % at 2,000 R/min |
| 96035B |
95 % at 5,000 R/min |
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| Wall Material |
| 96020C |
Composite graphite-filled thermoplastic |
| 96035B |
Graphite-coated acrylic (methylmethacrylate) |
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| Window Material |
| 96020C |
0.76 mm thick, graphite-coated polycarbonate |
| 96035B |
Both entrance windows are made of 0.25 mm graphite-coated polycarbonate |
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| Window Density |
| 96020C |
91 mg/cm2 |
| 96035B |
32 mg/cm2 |
|
| Active Window Area |
| 96020C |
100 cm2, centered within the chamber body |
| 96035B |
Each side of the chamber has a circular active window region centered 7.1 mm further from the BNC connector than the center of the chamber body; active window regions have an area of 12.32 cm2 |
|
| Collector Plate |
| 96020C |
0.8 mm thick graphite-coated acrylic plate, 10.80 cm in diameter; 2.16 cm x 2.85 cm guard region electrically isolated from collector area |
| 96035B |
0.25 mm thick, centrally mounted, graphite-coated, polycarbonate plate, 3.18 cm, ± 0.01 cm in diameter; 1.27 cm x 0.89 cm guard region is electrically isolated from the collector area |
|
| Connector |
| 96020C/96035B |
Side-mounted, triaxial, two-lug BNC connector |
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| Calibration |
| 96020C |
Standard calibration performed at H60 (NIST defined as 60 kVp, first HVL of 6 mm Al, homogeneity coefficient of 94) |
| 96035B |
Standard calibration performed at one diagnostic and one mammographic beam quality |
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Calibration factors normalized to 22 °C and 760 mmHg Diagnostic Unattenuated Beam |
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Calibration on diagnostic side of chamber is performed at M80 (NIST defined as 80 kVp, first HVL of 2.97 mm Al, homogeneity coefficient of 57) Mammographic Beam |
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Calibration on mammographic side performed at Mo/Mo28 (NIST defined as 28 kVp, first HVL of 0.332 mm Al, homogeneity coefficient of 74.3) or MV30 (PTB defined as 30 kVp, first HVL of 0.337 mm Al) |
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| Measurement Range |
| Invasive mAs (With Shunt) mA/mAs Ranges* |
| Min to Max |
0.00 to 99.99 |
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100.0 to 999.9 |
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1000 to 1999 |
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*mAs measurements are fully
auto-ranging, so values
are display ranges only |
|
| Non-Invasive mAs (with clamp) mA/mAs Ranges |
| Min to Max |
0.0 to 999.9 |
| |
1000 to 3999 |
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| Accuracy |
| Invasive mAs (With Shunt) |
|
