I
NTERNAL
M
EASURING
R
ANGES
Only under the condition that at least
4 consecutive zero adjustment
cycles
are within a specified tolerance, the zero value will be accepted. In
case a measuring value exceeds the specified tolerance (caused e.g. by a
contaminated measuring chamber or by leaks etc.) the number of
previous measured values will be reset to zero.
2240 PROcheck
will
then renew its effort for zero adjustment. If after 50 attempts no
consecutive values prove to be correct, the instrument will stop zero
adjustment and indicate a failure (see
Chapter 6
).
D
URATION
OF
Z
ERO
A
DJUSTMENT
Duration of zero adjustment is approx. 1 minutes in a favorable case. In
the most unfavorable case this operation may take up to 15 minutes if e.g.
the gas path or the measuring chamber is contaminated. If no correct zero
adjustment is being achieved within this time frame, then a failure
indication will be given (see
Chapter 6
).
D
ISPLAY
During the zero adjustment the display will show the measuring range
actually under test and additionally the progress of zero adjustment:
RNG
indicates the actual measuring range, The value after the “
A”
shows the number of attempts and the value after the “
S”
shows the
number of results lying within the specified tolerance bracket.
After successful zero adjustment the instrument normally switches to
"Stand-By-Mode"
Depending on the configuration of the instrument this stand-by mode will
either be maintained or it will automatically switch over to measuring at
a pre-configured channel.
A
UTOMATIC
Z
ERO
A
DJUSTMENT
2240 PROcheck
automatically carries out a zero adjustment procedure
after every activation of the mains switch.
14
