Instrument Operation and Calibration
Starting Materials:
Handheld Little Dipper
Calibration Solutions
Deionized water or sample water devoid of organics
Darkened Container
To calibrate the Handheld Little Dipper for PTSA, you should use the calibration solution with part number 10-608, which is PTSA dye at a concentration of 100 ppb in a 1-liter volume. Ensure you follow the calibration procedures as outlined in the instrument's manual or provided documentation to achieve accurate results. 998-2853.pdf
Instrument Power Up and Sample analysis
To turn on the Handheld Little Dipper, press the power button.
Insert the sensor in the sample at an angle with the cap fully submerged.
Example below:Shake gently to make sure all bubbles are purged from the cap. Then vertically straighten the device.
Press the READ button.
Calibration Procedure
Note: Handheld Little Dipper is calibrated when shipped. Only re-calibrate if unit does not read 100 ± 3% for the appropriate Standard Solution. Use P/N 10-608 PTSA 100 ppb.
Calibrating to standard solution (Calibrating 100)
Prepare a 1 Liter darkened beaker with the PTSA standard solution.
To calibrate, press and hold the READ button while unit is off. If taking measurements with the cap, ensure cap is still on the Handheld Little Dipper while doing all calibrations. If you choose to measure without the cap, then have calibrations with the cap off.
While holding the READ button, press and hold the Power button until 100 appears on the screen. Release both buttons.
Insert the sensor in the standard at an angle with the cap fully submerged, shake gently to make sure all bubbles are purged from the cap, straighten sensor vertically from an angle, and press the READ button.
The display will flash “td” four times and then the unit will automatically turn off.
Calibrating the blank (Calibrating 0)
Repeat Step 2 from Calibration 100 to begin calibration for 0.
Repeat Step 3 of continuing to hold both buttons, the 100 will appear and after 15 seconds, the 0 will now display. Release both buttons.
Hold sensor away from yourself at least 4 feet away from any reflective surfaces, direct sunlight, or the ground and press the READ button.
The display will flash “td” four times and then the unit will automatically turn off.
You can confirm the calibration by turning the unit on and pressing the READ button while the unit is facing away from reflective surfaces and the ground. Display should show 0.
At this point the Handheld Little Dipper is calibrated. You can confirm the calibration by turning the unit on and pressing the READ button while the unit is in the standard solution. Readings should be 100 ± 3%.
Troubleshooting with Calibration
Our Handheld Little Dipper performs optimally when the cap is on during readings. However, if you need to perform a calibration without the cap, please keep the following key points in mind:
Accuracy: Calibration without the cap may affect the accuracy of your readings. Ensure that the environment is consistent and controlled.
Consistency: Always calibrate under the same conditions to maintain reliable results. Any changes in lighting or temperature can impact calibration. We recommend calibration at room temperature.
Documentation: Record the calibration conditions and any deviations from standard procedures for future reference and troubleshooting.
Safety: Handle the device carefully to avoid contamination or water damage during the calibration process without the cap.
Following these guidelines will help ensure that your Handheld Little Dipper remains accurate and reliable, even when calibrating without the cap. To maintain accuracy and reliability of your Handheld Little Dipper, calibrate it in a 1-liter container, which offers sufficient space for optimal sensor function. Ensure the sensor face is positioned at least 3 inches from any surface to achieve the best readings.
An example of an issue with calibrating without the Handheld Little Dipper cap is using a clear glass beaker or a fluorescent plastic container. Light emitted by the sensor can reflect back into it, leading to inconsistent or variable readings.
Since the Handheld Little Dipper uses a UV light, it is harder to demonstrate this problem. Below is our other unit called the FluoroSense which has a visible orange light.
It is advisable to use a darkened beaker, or one wrapped with black electrical tape to minimize ambient light and fluorescent light reflections. The images below illustrate how the FluoroSense shows minimal reflected orange light, demonstrating the effectiveness of this approach.
Below is an image of the Handheld Little Dipper using a darkened beaker with PTSA 199 ppb. Notice how the UV light is barely visible in a darkened beaker.