The absolute accuracy of the instrument will be depen-
dent on the accuracy of the user reference blocks and 
will no longer be to the accuracy stated in the “Speci-
fi cations” chapter of these instructions. It is not rec-
ommended that measurements are made outside the 
range of the two sample values; as the accuracy will 
be totally dependent on the absolute accuracy of the 
user reference blocks.
For the relative reading accuracy to be the same as 
for GE Inspection Technologies STD blocks, the two 
user reference block values must be accurate and lie 
either side of the measurement range. e.g. If the mea-
surement range is to be between 40 and 45 % IACS 
then STD 1 should ideally be 50 % IACS or more and 
STD 2 should be 35 % IACS or less. 
It is possible to set the AutoSigma 3000 DL by using 
one user reference block and one STD block, provided 
that the above rules are complied with, the absolute 
accuracy will again be dependent on the accuracy of 
the user reference block.
5.5  Probe setting (SET PROBE)
Before the probe setting on the reference blocks can 
take place, the value of the blocks must be entered in 
the STD 1 and STD 2 menu slots in the units selected 
(i.e. IACS or MS/m) The probe code must also be ap-
propriate to the probe in use. Proceed following sec-
tion 5.4 to set the reference block values. Then with 
the instrument on and in the Measurement mode:
Entering reference block values
Operation
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  Issue 04, 06/2007  AutoSigma 3000