Compliance Verification For Free And Total Chlorine Testing - eXact Micro 7+ Instruction Manual

About Your eXact
In order to save power, the meter is designed to turn off after 3 minutes (timed from the last button pressed).
Should the meter turn off in the middle of a test, the last stored zero in the meter will remain valid when the
meter is turned on again. Also, the test result is stored in memory for easy retrieval.
The eXact Micro 7+ meter is controlled by three buttons:
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1. ZERO/ON: When first pressed, this button turns the meter on. When the meter is on and this button is
pressed, it zeroes the sample in the cell. Once the meter is zeroed, this zero value applies to all parameters
and is stored and retained even when meter turns off. However, it is recommended that each new water
sample analyzed is zeroed before testing, to maximize sensitivity and accuracy.
2. MENU: With each press, the MENU button advances through the tests in the following sequence: CL1,
PH2, BR3, AL4, CA5, CU6, TR7. Each test menu can store up to 20 results. To retrieve the stored results,
go to the desired test using the MENU key. When the desired test is displayed, press and hold down the
MENU key. Continue holding down the MENU key to scroll the stored results for that test, starting with the
most recent result. The meter will display, from memory, the last 20 readings in sequence beginning with -20,
which is the latest result, followed by -19, which is the 2
result retained. Only the last 20 readings are stored in each menu. This meter is able to store 140 results in
memory (20 in each menu).
3. READ: When pressed once, this button starts the timer for the parameter being tested. When pressed a
second time the meter exits the timer and immediately prepares to colorimetrically measure the sample, and
simultaneously stores the measurement in memory.
If the parameter being measured is below or above the detection range, the display will show "LO" (Under
Range) or "HI" (Over Range), respectively. This feature is menu specific and does not apply to all parameters.
About The Accuracy/Calibration of The Micro 7+ System
The algorithms in the software reflect the best correlation of the eXact
AWWA, US EPA , DIN, and ISO reference test methods for chlorine. Studies show that the eXact
7+ System repeatedly agrees with an EPA Compliant reference method greater than 99% (R
0 - 6.0 ppm - see page 6). Another study comparing meters made by Palintest, Hach, and Tintometer is
found on page 12. The eXact
your convenience. You can expect the fixed calibrations in the meter to be valid for the life of the meter
because of the quality, Long-Life LED, the photo cell, and the software as written into the meter. This is
why the meter comes with a 5-Year Warranty.
Compliance Verification for Free and Total Chlorine Testing
This DPD test system is accepted by most state health departments because this test is USEPA
accepted for testing requirements for Free and Total Chlorine. The Micro 7+ meter uses a wavelength
of 525nm; and the compliance requirement is that the colorimeter wavelength is between 490 and
530nm. The eXact Strip Micro CL (DPD-1) uses the same reagents and proportions, and the resulting
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solution pH is maintained between 6.2 and 6.5 as specified by AWWA (American Water Works
Association) method 4500-Cl G. It should be understood that the USEPA does not "approve" commer-
cial DPD delivery systems such as reagent powder pillows, tablets, dispensers, or eXact
delivery devices. The eXact
(DPD-3) or the eXact
ments because the eXact
table below); therefore, the system is compliant. Likewise, AWWA proportions are followed as required
for Total Chlorine measurements using Potassium Iodide.
Micro 7+ Advanced Photometric System has been factory calibrated for
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Strip Micro CL (DPD-1) for Free Chlorine, and the eXact
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Strip Micro CL (DPD-4) for Total Chlorine meet your reportable testing require-
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Strip Micro CL delivers the same chemicals in identical proportions (see
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Component
(Free Chlorine)
Anhydrous DPD sulfate
Anhydrous Na HPO
2
Anhydrous KH PO
2
EDTA
Micro 7+ Instrument
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latest result, etc; and finally -01, which is the oldest
nd
AWWA
4500-Cl G
1.5%
33.4%
4
64.0%
Na
4 2
1.1%
3
Micro 7+ Systems against the
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Strip Micro CL
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eXact
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DPD-1
1.5%
33.4%
64.0%
1.1%
Micro
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= 0.9912,
2
Strip DPD