Van Walt CT12 Operating Instructions Manual page 9

Compact turbimeter

Table of Contents

VAN WALT

Monitoring your needs

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 :

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.

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.

Compact Turbimeter

Operating Instructions

Table of Contents