Arsenometer HMAS100
Instruction Manual v2.0
Altering deposition times
The standard default deposition time of 60 seconds is suitable for all analysis
down to 5ppb for most elements, 10ppb for arsenic. To increase accuracy for the
lower levels an increased deposition time is recommended. If the user expects the
analysis to be higher then a shorter deposition time should be used. This can be
adjusted when prompted to choose a deposition time at the beginning of the test
methods.
30, 60 or 120 seconds can be selected by moving the joystick to the right and to
the left on this screen and then pushing the centre of the joystick to accept it.
Deposition time Concentration range
30 seconds 50ppb to 500ppb
60 seconds 10ppb to 50ppb
120 seconds <10ppb
Suggested ranges for choosing deposition times
The instrument has been designed to have a maximum reading of 500ppb. Should the
user wish to measure higher than this they will need to dilute the sample. For example, if
the user wishes to measure 600ppb dilute the sample by half and then multiply the result
by 2.
Always dilute with water that will not contribute to the heavy metals being
tested. Deionised water is ideal.
Background
subtraction
Background subtraction
is recommended to be used for all of the analyses and is the
default setting. It is particularly important for the analysis of Hg and As.
