ULTRAPEN
X2
™ PTBT6 Operation Manual
Nitrate Concentration and Temperature Pen for Use with your Mobile Device Running the PTBTX2™ App
PTBT6OM-X2 01-20
8
TABLE 2
Spike References for Different Sample Concentrations for 10 mL Sample Volume (
V
/mL)
Measured Sample Concentration
(ppm
NO
3
–
-N
)
×100 µL
pipette
Reference Solution
(ppm
NO
3
–
-N
)
1-3
1
100
3-9
3
100
9-20
1
1000
20-60
3
1000
•
Add
n
spikes (volume increase:
𝑽
𝒂𝒅𝒅
=0.1×n/mL) of standard solution (Cs/ppm) to the sample solution after measurement
(C1/ppm) and swirl for mixing.
•
Take the 2nd measurement (C2/ppm) and calculate the recovery using the following equation:
𝑅𝑒𝑐𝑜𝑣𝑒𝑟𝑦(%) =
𝐶
*
× 100
𝑉 × 𝐶
;
+𝑉
MNN
× 𝐶
O
× (1/(1 − 𝐷
S
))
(𝑉
MNN
+ 𝑉)
Where:
Df - the dilution factor when spiking unprepared standard solutions:
o
1/51 for using NISA and
½
for using NISB.
o
If adding prepared standard solutions, Df is 0.
The recovery should be within 10% of the expected value.
o
If not, the measurement result may not be reliable.
o
The source of error should be identified and the measurement should be redone after correction.
CALIBRATION
Myron L
®
Company recommends calibrating the PTBT6 before each series of tests, depending on usage.
I. GENERAL NOTES:
•
Nitrate sensor should be conditioned prior to performing a calibration (see SENSOR CONDITIONING, above).
•
The PTBT6 offers 1-point or 2-point calibration and is calibrated in nitrate as nitrogen (
NO
3
–
-N
) using 1, 10, 100, or 1000
ppm reference solutions.
•
For greatest accuracy complete a 2-point calibration, selecting the closest reference solutions in the same range as your
expected test solution range (example: If you are measuring test solutions in the range of 200 to 400 ppm
NO
3
–
-N
, use
100 ppm and 1000 ppm reference solutions to calibrate the PTBT6.
•
Reference solutions must be prepared prior to use.
•
Calibration is always done in nitrate as nitrogen (
NO
3
–
-N
) even if your PTBT6 is set to measure in nitrate (
NO
3
). To select
the optimal reference solutions and to verify calibration, see the Conversion Table below.
TABLE 3
Conversion Table
Reference Solution
Value in
NO
3
–
-N
Value in (NO
3
-
)
N1SOL
1 ppm
4.4 ppm
N10SOL
10 ppm
44 ppm
N100SOL
100 ppm
440 ppm
N1000SOL
1000 ppm
4400 ppm
NOTES:
•
Always start with the lower calibration point first.
•
For greatest accuracy, keep the temperature of the prepared reference solution(s) the same as the test solution. The
temperature difference should be within ±2°C.
