37
Calibration
3.6
Turbidity
Standards
For best results, YSI recommends the following standards for turbidity calibration:
Other standards may be acceptable as long as they have been prepared according to details in Standard Methods for
the Treatment of Water and Wastewater (Section 2130 B). These standards include:
• YSI Certified AMCO-AEPA polymer-based standards (see above)
• Hach StablCal™ standards in various NTU denominations
• Dilutions of 4000 NTU formazin concentrate purchased from Hach
• Other formazin standards prepared according to the Standard Methods
The use of standards other than those mentioned above will result in calibration errors and inaccurate field readings.
It is important to use the same type of standard for all calibration points; do not mix formazin and polymer-based
standards for different points in a multi-point calibration.
When using an alternative standard (non-YSI), calibration can be completed using the following limits:
Min
Max
Unit
1st Calibration Point
0.0
1.0
FNU or NTU
2nd Calibration Point
5.0
200
FNU or NTU
3rd Calibration Point
400
4000
FNU or NTU
Calibration Point Standard Value
1
0 FNU [SKU: 608000]
2
12.4 FNU [SKU: 607200] or 124 FNU [SKU: 607300]
3
1010 FNU [SKU: 607400]
