Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
Compact Turbimeter
8
VAN WALT
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Total Suspended Solids – When using the Compact Turbimeter in Total Suspended
Solids Reading mode, a calibration is required to set the relationship between the
measured turbidity values and the true suspended solids value, determined by
gravimetric methods. This calibration can either be an assigned series of values
from the results log or a simple algorithm with factors provided by the user. This
relationship is typically a straight line and hence the factors consist of a slope and
intercept. The Compact Turbimeter has two methods of generating the data for
relating the measurement of turbidity to suspended solids :
1. Correlation – Using the stored turbidity data from the instrument log and relating
it to manually entered Suspended Solids data derived from elsewhere. The
minimum number of correlation points required is one as the zero point is used
by default. A maximum number of 50 data points can be used.
2. Factor – Using data manipulated externally, a slope and intercept for the
straight line relationship can be entered directly.
Calibrating the Compact Turbimeter
SDVB
Select Calibration and press ‘OK’. Choose SDVB and press ‘OK’. Select the 0.10
NTU standard and insert into the sample chamber with the orientation mark facing
forward. Use the Up/Down buttons to adjust the value on screen to that on the
standard and press ‘Read’. Repeat the process for the 20 NTU, 100 NTU and 800
NTU standards. On completion of the process the Compact Turbimeter screen will
show ‘Successful’. Press ‘Back’ to leave the calibration process and return to the
Calibration menu.
To cease calibration during the data capture phase press ‘Cancel’. To cease the
calibration process at any step press ‘Back’ (calibration data will be discarded).
The time, date and Operator ID are stored in the calibration log for GLP compliance.
Total Suspended Solids – Correlation
Select Calibration and press ‘OK’. Select Total Suspended Solids and press ‘OK’.
If the Sample ID has already been created use the Up/Down arrows to highlight and
press ‘OK’ to select. If a new Sample ID is required, move the highlight to a blank
area and press ‘New’.
Create the new Sample ID using the Up/Down buttons to select characters as
describe in the System section.
