Thermo Fisher Scientific TN100 Turbidimeter - Manual (Page 28)

Instruction Manual TN-100/ T-100
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2. Turbidity-free water can be obtained by filtering deionized water through a < 0.2μm
filter membrane with precision-sized pores.
3. Measure the volume of the sample before dilution and record the value in ml (Vs).
4. Take a known volume (Vd) of dilution water and add it to the sample.
5. Pour 10 ml of the diluted sample in a clean vial and measure the turbidity of the
diluted sample. Record this value in NTU (Td).
6. Calculate the true turbidity (T) of the original sample - in NTU - using the following
formula:
T = Td * (Vs + Vd) / Vs
Example:
 Dilute 20 ml of the original sample (whose turbidity is above 1000NTU)
with 50 ml of dilution water.
 Measure the turbidity of the diluted sample.
 If the reading is 300 NTU, the turbidity of the original sample is 1050
NTU. (In this case: Td=300NTU, Vs=20ml, Vd=50ml, so T = 300 *
(20+50) / 20 = 300*70/20 = 21000/20 = 1050)
10. Warranty
The TN-100/ T-100 meter is supplied with a 2-year warranty from manufacturing
defects and calibration standards for 6 months.
If repair or adjustment is necessary and has not been the result of abuse or misuse
within the designated period, please return – freight pre-paid – and correction will be
made without charge. Eutech Instruments/ Oakton Instruments will determine if the
product problem is due to deviations or customer misuse.
Out of warranty products will be repaired on a charged basis.
Exclusions
The warranty on your instrument shall not apply to defects resulting from:
• Improper or inadequate maintenance by customer
• Unauthorized modification or misuse
• Operation outside of the environment specifications of the products
Waterproof Seal: Opening the instrument enclosure (excluding the battery
compartment) may void the warranty.