Instrument Calibration; Calibration Standards - wtw Turb 2000 Operating Manual

Instrument calibration

4 Instrument calibration
The instrument was calibrated and tested prior to leaving the factory. Therefore, it is possible to use the
instrument directly out of the box. Under normal conditions, recalibration is recommended at least once
1
every three months .
Relay contacts are held at the last valid condition and will not change state while the instrument is in the
calibration and/or in the configuration mode. While in the calibration mode, the instrument has a time-
out feature that automatically returns the system operation to the AUTO mode after a fifteen (15) minute
period of inactivity.
4.1

Calibration standards

If the Turb 2000 series will be used over the entire range of 0.02 to 1000 NTU a complete calibration as
described below will be required.
If instrument accuracy is only required below 10 NTU (below 1 NTU for Turb 2110), such as potable
water, a calibration may be performed using only a 10 NTU and a 0.02 NTU standard (1.0 NTU and
0.02 NTU for Turb 2110). To calibrate starting at the 10 NTU, press the button to bypass the 1000
NTU and proceed to section 4.2 C
We recommend that the following materials be used during calibration to achieve the full-scale accuracy
stated in this manual:
•
For Turb 2000/2020/2100/2120 (Kal Kit Turb/DW):
0.02 NTU Calibration Standard
10.0 NTU Calibration Standard
1000 NTU Calibration Standard
•
For Turb 2110 (ProCal-Kit):
0.02 NTU Calibration Standard
1.0 NTU Calibration Standard
10.0 NTU Calibration Standard
See section 11 R
EPLACEMENT PARTS AND ACCESSORIES
It is well known that diluted Formazin is unstable. The WTW primary calibration standards are more
long-term stable than Formazin and have a long shelf life. Prior to recalibration, review the expiration
dates, to ensure that the standards have not expired.
Details on the handling of calibration standards see section 5.1.
1
The EPA recommends that on-line turbidimeters be calibrated with a primary standard at least once every three
months if they are to be used for EPA reporting.
18
ALIBRATION PROCEDURES
, step 5.
for ordering information.
Turb 2000 Series
ba75695e03 10/2013