Aquaprobe
®
AP-700, AP-800 & AP-2000 Instruction Manual
10401-00870 Rev R
26.3. I can see algae in the water but my sensor is giving low readings. Why?
Aquaread
®
Chlorophyll and Blue-Green Algae sensors are not designed to measure
floating macroscopic (visible to the naked eye) algae or plant material.
The sensors measure the fluorescence from the microscopic phytoplankton suspended
within the body of the water below the surface. Carpets of floating algae are often seen on
environmental water that has low subsurface phytoplankton concentrations. In these
circumstances, the fluorescent algae sensors will return low readings.
26.4. What is the Range and Resolution of the Optical Electrodes?
Range
0 – 3000 NTU
Resolution
2 Auto-range scales: 0.0 - 99.9 NTU, 100 - 3000 NTU
Turbidity
Accuracy
± 5% of auto-ranged scale
MLD
(1)
0.0 NTU
MLR
(2)
5.0 NTU
Range
0 – 500.0 µg/L (ppb)
Resolution
2 Auto-range scales: 0.00 - 99.99 µg/L, 100.0 - 500.0 µg/L
Chlorophyll
Repeatability
± 5% of reading
MLD
(1)
0.1µg/L
MLR
(2)
5 µg/L
Phycocyanin
(BGA-PC)
(Freshwater Blue
-Green Algae)
Range
0 – 300,000 cells/mL
Resolution
1 cell/mL
Repeatability
± 10% of reading
MLD
(1)
200 cells/mL
Phycoerythrin
(BGA-PE)
(Marine Blue-
Green Algae)
Range
0 – 200,000 cells/mL
Resolution
1 cell/mL
Repeatability
± 10% of reading
MLD
(1)
400 cells/mL
Rhodamine
WT Dye
Range
0 – 500 µg/L (ppb)
Resolution
2 Auto-range scales: 0.00 - 99.99 µg/L, 100.0 - 500.0 µg/L
Repeatability
± 5% of reading
MLD
(1)
0.1 µg/L
MLR
(2)
5 µg/L
Fluorescein
Dye
Range
0 – 500 µg/L (ppb)
Resolution
2 Auto-range scales: 0.00 - 99.99 µg/L, 100.0 - 500.0 µg/L
Repeatability
± 5% of reading
MLD
(1)
0.1 µg/L
MLR
(2)
5 µg/L
Range
0 – 10,000 µg/L (ppb) (Napthalene)
Refined Oil
Resolution
0.1 µg/L
Repeatability
± 10% of reading
MLD
(1)
10 µg/L (Napthalene)
CDOM/FDOM
Range
0 – 20,000 µg/L (ppb) (Quinine Sulphate)
Resolution
2 Auto-range scales: 0.0 – 9,999.9 µg/L, 10,000 – 20,000 µg/L
Repeatability
± 10% of reading
MLD
(1)
10 µg/L (Quinine Sulphate)
Aquaread® Ltd reserves the right to change specifications without notice
Notes:
1. MLD (Minimmum Level of Detection) is the minimum value the electrode is physically capable of
measuring.
2. MLR (Minimum Level of Repeatability) is the value below which optical electrode readings become
generally unreliable and unrepeatable (unless taken under ideal conditions) due to interfering factors such
as refraction from visible air bubbles and microscopic aeration.
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®
Ltd.
www.aquaread.com
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