Farmer Chamber

Model/Serial: 30001-811 (purchased: 1996)
Model/Serial: 30001-812 (purchased: 1996)
Model/Serial: 30010-002591 (purchased: 2014)
Model/Serial: 30010-002592 (purchased: 2014)

Description: Verified ionization chamber (0.6 cm3) for absolute dosimetry. We use this non-waterproof chamber with Unidos or Unidoswebline in the home-made gantry-mounted PMMA phantom to check linac dose output during weekly linac QA.

Calibration History: Chamber 811 + Unidos 10396

Date NW U ppol (60Co) ps (60Co) NW' [Gy/C] Laboratory
26.03.1996 1.00 0.04 5.132E+07 PTW
20.05.1996 1.024 0.015 5.132E+07 BEV
03.08.1998 1.03 0.02 5.132E+07 BEV
08.03.2001 1.03 0.02 5.132E+07 BEV
03.02.2003 1.03 0.01 5.132E+07 BEV
05.04.2005 1.030 0.01 5.132E+07 BEV
29.11.2007 1.034 0.014 5.132E+07 Seibersdorf
29.04.2009 1.030 0.014 5.132E+07 Seibersdorf
27.04.2012 1.032 0.014 5.132E+07 Seibersdorf
15.04.2014 1.035 0.014 5.132E+07 Seibersdorf

Calibration History: Chamber 811 + Unidoswebline

Date NW U ppol (60Co) ps (60Co) NW' [Gy/C] Laboratory
20.04.2006 1.030 0.014 5.132E+07 Seibersdorf
13.06.2008 1.030 0.014 5.132E+07 Seibersdorf
06.09.2010 1.032 0.014 0.999 1.000 5.132E+07 Seibersdorf
27.04.2012 1.033 0.014 1.000 1.000 5.132E+07 Seibersdorf
15.04.2014 1.034 0.014 1.000 1.000 5.132E+07 Seibersdorf

60-Co calibration factors

Calibration History: Chamber 812 + Unidos 10398

Date NW U ppol (60Co) ps (60Co) NW' [Gy/C] Laboratory
26.03.1996 1.00 0.04 5.071E+07 PTW
20.05.1996 1.024 0.015 5.071E+07 BEV
24.11.1998 1.030 0.02 5.071E+07 BEV
29.11.2000 1.030 0.02 5.071E+07 BEV
06.08.2002 1.040 0.01 5.071E+07 BEV
14.04.2003 1.030 0.01 5.071E+07 BEV
20.04.2005 1.030 0.01 5.071E+07 BEV
22.02.2007 1.025 0.014 5.071E+07 Seibersdorf
20.11.2009 1.033 0.014 0.999 1.000 5.071E+07 Seibersdorf
27.06.2011 1.035 0.014 0.999 1.000 5.071E+07 Seibersdorf
16.04.2013 1.040 0.014 1.000 not possible 5.071E+07 Seibersdorf

60-Co calibration factors

Notes

60-Co calibration factors

Logbook

Date Event
26.03.1996 S/N 811 and S/N 812: initial calibration by PTW.
16.04.2013 S/N 812: Seibersdorf cannot determine saturation correction factor. Stabilization after voltage change takes too long.
03.06.2014 Received new S/N 2601 and 2602 (cable length: 10 m).
10.06.2014 Dropped S/N 2601: tip broken.
11.06.2014 Both chambers sent to PTW for repair of S/N 2601 and reduction of cable length to 1.2 m.
17.07.2014 Delivery of two new Farmer chambers: S/N 2591, S/N 2592

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