PC Electrometer is a dual channel reference class electrometer for absolute dose calibration. The system is designed for accuracy and convenience. It offers small size (0.4 kg), near no warm-up time (< 1 minute), and complete operation through USB, with no batteries or external power connections.
PC Electrometer sampling is every 500 ms. This graph represents the dynamic range of the PC Electrometer when sampling is lowered to 100 ms (not available in commercial systems). Each step in this graph of total charge indicates a linac pulse as measured with a 0.6 cc chamber. PC Electrometer clearly shows the increase in linac pulse frequency as a function of dose rate. From 80 MU/min, the additional pulses are 1, 2, 3, and 4 for the respective rates of 160, 240, 320, 400.
Fast sampling makes PDD curves smooth and accurate when measured with the PC Electrometer and 1D SCANNER. The PDD curve below is an un-smoothed ratio of Field to Reference, using 0.6 cc Farmer type chambers.
The PC Electrometer directly connects to the 1D SCANNER for monthly and annual QA
|Warm Up Time:||< 1.0 min|
|Charge Range:||2 pC – 10 mC, 15 fC resolution|
|Current Range (Continuous):||Low: 2 pA – 50 nA|
|Current Range (Pulsed):||0 -105 pC/pulse|
|Leakage Drift:||±0.001 pA|
|Display Update Frequency(s):||500 ms|
|Bias Voltage:||Adjustable, 0 to ±400 V|
|Non-linearity:||± 0.1% of full scale|
|Long Term Stability:||± 0.5%|
|Measurement Repeatability:||± 0.25% of full scale|
|A/C Converter:||16 bit|
|Operating System:||Windows XP, or 7 (32 or 64-bit)|
|Dimensions / Weight:||10.6 x 14.8 x 4.5 cm / 0.46 kg|