Thermo Scientific AquaSensors™ DataStick™ Measurement System User Guide
77
Inside the DataStick there are two concentration tables; the scratch table and the working table. The scratch table is used to store
the points written with the SUPNT command. If the points in the scratch table are valid, they are copied to the working table when the
SUTBL command is used. The points in the working table are used to convert the measured conductivity value into a concentration value.
The points in the scratch table can be read using the GSPNT command. The GSPNT command is available in DataStick firmware version
D3.21 or later. The DataStick firmware version can be obtained using the GCVSN command.
The points in the working table can be read using the GUPNT command. A point read from the working table using the GUPNT command
is automatically written to the scratch table. This helps to insure that the scratch table is always known and valid.
Figure 10. The inner workings of the User-Entered Concentration Table.
For the scratch table to be considered valid, the following must be true:
1. All successive conductivity point values must be
monotonic and increasing
and be within the bounds of 0 to 2,000,000.0
µS/cm.
2. The concentration values must be
monotonic and either increasing
or
decreasing
and be within the bounds of 0 to 99.99%.
3. If fewer than ten points are entered, then the scratch table must be terminated with a last point containing zero values.
Provided the above criteria are met, the points in the scratch table are transferred to the working table when the SUTBL command is used;
otherwise the current working table is retained.
0
Cond
Conc
0
0
20000
99.99
1
0
0
2
0
0
3
0
0
4
0
0
5
0
0
6
0
0
7
0
0
8
0
0
9
Scratch Table
SUTBL
(if scratch table
is valid)
Conductivity
scaling
User
GUPNT
GSPNT
SUPNT
0
Cond
Conc
0
20000
99.99
1
2
3
4
5
6
7
8
9
Working Table
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
