Specials

Get near-tissue equivalent thermoluminescence dosimetry (TLD) performance with a high-capacity reader for all types of TLD elements and health physics applications. The Thermo Scientific™ HARSHAW TLD Model 5500 Automatic Reader provides unattended operation for up to 50 dosimeters and accommodates TL chips, disks, rods and cubes in a broad variety of sizes. This reader is suitable for all kinds of applications that require TLD detectors. Clinical applications are: Radiotherapy planning verification, total body irradiation dose verification, critical organ dose verification, diagnostic dose studies including CT, and many others where measurement quality assurance is critical.

Compact, attractive reader has a linear, programmable heating system and a cooled photomultiplier tube with associated electronics to measure the TL light output. The WinREMS Software, which runs on a separate computer, provides the user interface, the reader control and the applications software.

  • Easy operation, service and maintenance
  • Measurement quality assurance
  • Unattended automatic operation for up to 50 dosimeters
  • Thermoelectric PMT cooler for maximum gain stability
  • Unattended automatic background subtraction capability
  • Multiple, programmable, linear time-temperature profiles; heating profile includes pre-heat, acquire and anneal cycles
  • Linear contactless hot gas heating with temperature capability up to 600°C (1112°F)
  • Seven decade dynamic acquisition ranges
  • 30 sec. cycle time per chip with normal TTP
  • Withstands 20mm drop on to concrete surface
  • Maintains specifications while exposed to light up to 1000 lux with cover in place
  • Options include glow curve deconvolution software, neutral density filters, and calibration software

Dosimetry Performance When Using LiF:Mg,Ti Chips (TLD-100):

  • Tissue equivalence: Nearly tissue equivalent
  • Batch uniformity: ±15% standard deviation from the batch mean, tighter on special request
  • Residual TL signal: <0.2% of reading, over the range, without annealing
  • Reuse: more than 500 per dosimeter with <10% sensitivity charge
  • Threshold: <10 µGy (1 mrad) based on 2.26 standard deviation of 10 repeat readings of an unexposed dosimeter

Light Detection System

  • Dynamic range: 7 decades
  • Warmup time: 30 min.
  • Linearity: <1% deviation
  • Stability: <1.0 mGy standard deviation of 10 consecutive readings
  • Dark current: <50 mGy 137Cs equivalent
  • Test light: temperature-stabilized LED
  • Stability: <0.5% standard deviation of 10 consecutive readings
  • Color: blue (wavelength 470 nm)

Dosimeter Heating System

  • Method: linear hot nitrogen gas
  • Time/Temperature Profile (TTP) temperature reproducibility: (±1°C)

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