3
•
If LIVE mode is selected you will be prompted to set the auto-off time: The display will alternate between “PUSH CONT”
and “[value] SEC”. Press and release repeatedly or push and hold to adjust the time out period. The display will scroll from
140 to 300 seconds, then repeat. When you have selected the desired timeout period, let the PT6 time out.
SENSOR CONDITIONING
If the sensor is new and/or has been stored dry, the sensor needs to be conditioned before calibration or measurement.
1.
Remove the protective cap. Rinse the sensor with clean water (preferably DI, RO, or distilled) and pat it dry with a clean soft
lint-free cloth.
2.
Fill the protective cap half-full with PREPARED calibration solution (with Nitrate ISA added, See PREPARING
CALIBRATION SOLUTION, below), carefully put the cap back on the sensor for conditioning (using caution as excess
solution may squirt out). It may take up to an hour for sensor to restore stable readings after dry storage.
NOTE: For best results, you should always condition your sensor using a PREPARED calibration solution with a value
close to the lower end of the concentration values you will be measuring.
CALIBRATION
The Myron L
®
Company recommends calibrating the PT6 before each series of tests, depending on usage. The PT6 offers 1-point
or 2-Point calibration and is calibrated in Nitrate as Nitrogen (NO
3
-
-N) using 1, 10, 100, or 1000 ppm Standard Solutions. For
greatest accuracy complete a 2-point calibration, selecting the closest Standard Solutions above and below your expected test
solution range (example: If you are measuring test solutions in the range of 200 to 400 ppm NO
3
-
-N, then you would want to
calibrate using 100 ppm and 1000 ppm Standard Solutions). Calibration solutions must be prepared prior to use.
Calibration is always done in Nitrate as Nitrogen (NO
3
-
-N) even if your PT6 is set to measure in Nitrate (NO
3
-
). To select the
optimal Standard Solutions and to verify calibration, see the CONVERSION TABLE below.
CONVERSION TABLE
Standard 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 prepared calibration solution(s) the same as the test solution. The
temperature difference should be within ±2
o
C.
•
Nitrate sensor should be conditioned prior to performing a calibration (see Sensor Conditioning, above).
I. PREPARING CALIBRATION SOLUTION
Calibration solution(s) must be prepared prior to calibration. For each standard solution selected:
1.
Fill a Graduated Cylinder to the 10 mL line with the Standard Solution.
2.
Add 200
µ
L of the Nitrate ISA solution to the Graduated Cylinder (using the supplied 100
µ
L pipette).
NOTE
: When using the pipette to draw, depress pipette to 1st stop, then place tip in ISA solution and release slowly. To
dispense, depress pipette completely to the 2
nd
stop.
NOTE
: Do not contaminate the pipette tip by touching it with your fingers or setting it in a dirty toolbox. Do not dip the
pipette tip in the calibration solution as this will cause cross-contamination between solutions.
3.
Replace the cap on the Graduated Cylinder and shake well to mix the prepared calibration solution.
II. 2-POINT CALIBRATION
To perform a 2-Point calibration you will need two prepared calibration solutions, clean water (preferably DI, RO, or distilled),
and a clean, dry, lint-free cloth.
1.
Remove the protective cap. Rinse the sensor for about 5 seconds with clean water (preferably DI, RO, or distilled) and pat it
dry with a clean soft lint-free cloth.
2.
Press and release the push button to turn the PT6 ON.
3.
Push and hold the push button to enter menu mode.
4.
Release the button while “CAL” is displayed. The display will alternate between “PUSHnHLD” and “CAL”.
5.
Push and hold the push button. The display will alternate between “1ppm”, “10ppm”, “100ppm”, “1000ppm”, and “ESC”.
