User Manual

3
Section 1 Specifications
Specifications are subject to change without notice.
Table 1 1720E Low Range Specifications
Range 0–100 nephelometric turbidity units (NTU)
Measurement Units mg/L, NTU, TE/F, FTU, Degree
Accuracy
1
± 2% of reading or ± 0.02 NTU (whichever is greater) from 0 to 40 NTU;
± 5% of reading from 40 to 100 NTU (when calibration is performed at 20.0 NTU with the
offset turned off).
Linearity
1
Better than 1% 0–40 NTU on formazin. Allows for accurate calibration at high turbidity values.
Resolution (Displayed)
0.0001 NTU up to 9.9999 NTU; 0.001 NTU from 10.000 to 99.999 NTU; 0.01 NTU at 100.00
NTU
Repeatability Better than ±1.0% of reading or ±0.002 NTU, whichever is greater
Response Time
For a full-scale step change, initial response in 1 minute, 15 seconds. Varies with flow rate,
see the table below. The response time is also dependent on the signal averaging time, which
is user selectable.
Sample Flow Required 250 to 750 mL/minute
Storage Temperature –20 to 60 °C (–4 to 140 °F)
Operating Temperature 0 to 50 °C (32–122 °F) for single sensor system, 0 to 40 °C (32–104 °F) for two sensor system
Sample Temperature
Range
0 to 70 °C
Operating Humidity 5 to 95% non-condensing
Power Requirements 12 VDC ± 5%, 12.5 Watts maximum
Sample Inlet Fitting
1
/8 barb fitting to ¼-inch NPT male adapter
Signal Average Time no averaging, 6, 30, 60, and 90 seconds, user selectable. Default is 30 seconds.
Dimensions Turbidimeter body and cap: 25.4 x 30.5 x 40.6 cm (10 x 12 x 16 inches)
Sensor Cable Length 2 m (6.6 ft); Optional 7.62 m (25 ft)
Mounting Options Turbidimeter Body and Head Assembly: Wall; floor stand
Shipping Weight
1720E Series 2 Turbidimeter and Controller: 6.31 kg (13.5 lb); 1720E Turbidimeter only: 4.71
kg (10 lb)
Calibration Methods
1. StablCal
®
(stabilized formazin) – primary or wet calibration of the instrument.
Recommended at 20.0 NTU.
2. Formazin – user-prepared primary or wet calibration of the instrument. Recommended at
20.0 NTU.
3. Multi-sensor calibration – Performed with a specialized calibration procedure for up to
eight sensors on a single set of fresh StablCal
®
standards.
% Step Change
Flow Rate
750 500 250
10 1¼ minutes 1½ minutes 2½ minutes
50 2 minutes 2½ minutes 6 minutes
90 3½ minutes 3½ minutes 9 minutes
99 4 minutes 5 minutes 12 minutes