Micro Roentgen Survey Meter for Gamma and X-ray
The Fluke Model 451P Ion Chamber is used in a wide range of medical and health physics applications. The Model 451P Ion Chamber was designed to measure leakage and scatter around diagnostic X-ray and radiation therapy suites. Furthermore, the Model 451P is ideal for site surveys and is regularly used by X-ray manufacturers, radiation therapy, government agencies, state inspectors, research labs, biomedical technicians, and in airports for baggage inspection equipment maintenance. This Ion Chamber was manufactured by Victoreen which is now Fluke Biomedical.
- High sensitivity µR measurements of exposure and exposure rate
- Available with dose equivalent energy response (SI units)
- Fast response to measure radiation from leakage, scatter beams and pinholes
- Ergonomic, anti-fatigue handle with replaceable grip and wrist strap
- Excel add-in for Windows ® for data logging and selection of instrument operating parameters (optional)
- Low noise chamber bias supply for fast background reading
- Choice of bright, highly visible colors
- Easy touch keys
451P Ion Chamber Specifications
Radiation Detected: Gamma and X-rays above 25 keV
Operating Ranges
0-500
µR/h or 0-5 µSv/h
0-5 mR/h
or 0-50 µSv/h
0-50 mR/h
or 0-500 µSv/h
0-500
mR/h or 0-5 mSv/h
0-5 R/h
or 0-50 mSv/h
Accuracy: Within 10% of reading between 10% and 100% of full scale indication on any range, exclusive of energy response. Calibration source is Cs-137
Detector Chamber: 300 cc volume pressurized air ionization chamber to 6 atmospheres
Controls: ON/OFF and MODE
Automatic Features: Auto-zeroing, auto-ranging, and auto-backlight
451P Response Time: Analog response time from 10% to 90% of reading for a full scale step increase is dependent on operating range. Response time for a step increase in radiation exposure rate from background:
| Step Increase | Time |
|---|---|
| 400 µR/h | 4.8 seconds |
| 4 mR/hr | 3.3 seconds |
| 10 mR/hr | 4.3 seconds |
| 40 mR/hr | 4.5 seconds |
| 100 mR/hr | 2.7 seconds |
| 1 R/hr | 2 seconds |
| 4 R/hr | 2.7 seconds |
The following table shows time measured from 10% to 90% of final value for a step increase or decrease in exposure rate such that a range change does not occur. These values are the response times for the various ranges:
| Range 10%-90% | Time |
|---|---|
| 0-500 µR/h | 5 seconds |
| 0-5 mR/h | 2 seconds |
| 0-50 mR/hr | 1.8 seconds |
| 0-500 mR/hr | 1.8 seconds |
| 0-5 R/hr | 1.8 seconds |
Power: Two 9-volt alkaline, 200 hours operation
Display: LCD analog/digital with backlight
Warm-Up Time: Less than two minutes for initial operation when the instrument is in equilibrium with ambient temperature
Environmental:
Temperature Range: -20°C to + 50°C
Relative Humidity: 0 to 100%
Geotropism: Negligible
Typical Energy Dependence: Nitrogen gamma rays are 110% to 120% of indicated readings as determined at the University of Lowell
Dimensions: 4 in (w) x 8 in (d) x 6 in (h) (10 x 20 x 15 cm)
Weight: 2 lb 6 oz (1.07 kg)
Modes: Integrate mode operates continuously 30 seconds after the instrument has been turned on. Integration is performed even if the instrument is displaying in mR/h or R/h
Freeze mode will place a tick mark on the bar graph display to hold on the peak displayed value. The unit will continue to read and display current radiation values.
| Model # | Part # |
|---|---|
| DS 451P Ion Chamber | 451P-RYR |
| 451 XL Software/Cable | 451EXL |
