Focustronic Mastertonic, Руководство пользователя

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If I suspect MT is not measure correct, or just want to double
check
If Mastertronic is correctly calibrated by the user and you use accurate reagents, the
accuracy is as stated as in user manual.
Here is some tips and things to check if you suspect a value is not correct from
MT
4) Just do a manual test with exact same reagent (
same batch and preferable
from same bottles ) as in Mastertronic. If difference its likely to be the calibration,
if no difference, MT is good calibrated. If no difference and you know the value is
incorrect (see point 2) , its an issue with the reagent.
2) Use a manual hobby test kit, not out of date. Do a measurement with this test kit
on a reference fluid (ATI has one for instance), and calculate a correction factor.
Now do a test with the manual test kit also on your tank and correct the
measured value with the factor. Now this value is very likely to be the true value.
This true value should be close to a fresh Mastertronic measurement, within its
stated accuracy. If not, its either MT is not calibrated correct, or issue with the
reagent. (see point 1).
3) Concerning ICP and PO
4
its also worth to take note: ICP measures all
phosphorus, not just the inorganic PO
4
. That means that if the sample
to the ICP contains some organics, ICP may give you a false high value of PO
4
,
as ICP just measures the P atoms, and does not take into account where this P
atom is coming from. This P value is then assumed by the ICP algorithm to have
its origin come 100% from PO
4
, which is not fully the truth. So for that reason, it´s
not always fully correct to compare an ICP based ”PO
4
” with a measured one.
The ICP can, due to the reasons above, sometimes give false high results for
PO
4.
4) During some circumstances it can be a minor “contamination conflict “ between
nitrate reagent and phosphate reagent. This is 100% solved by just avoid to do a
PO
4
immediately after a NO
3.
So if you want to do NO
3
and PO
4
after each other,
use the order PO
4
-NO
3
and not NO
3
-PO
4,
when you make the schedule. See
also here.
5) If you notice that the values, (specially Mg, Ca, KH) are always very close at the
max or min limits, then it could be
something wrong.
Mg
2+
790 - 1580 mg/l
Ca
2+
303 - 561 mg/l
KH 6.08 - 12.16 dKH