Aquameter
™
Series Instruction Manual
10401-00188 Rev M
10. RapidCal Calibration Method
10.1. About Calibration
Calibration is a very important part of successful water quality measurement and should be
carried out regularly as detailed in each separate section of this manual. A great deal of
development work has been put into simplifying and automating the calibration procedures
in the Aquameter in order to allow normal field operatives (as opposed to trained lab
technicians) to achieve quick and accurate results.
In order to standardise calibration techniques, Aquaread provide purpose made, amber
plastic, 300mL calibration bottles, some with non-reflective pads fitted to their bases. All
Aquaprobes are designed to be calibrated in these calibration bottles with both halves of
the Probe Sleeve fitted but
without the Sleeve End Cap fitted
.
Both halves of the Probe sleeve form an integral, working part of the Probe’s
measurement system, and MUST be fitted during calibration and measurement for
correct operation.
Whilst it is acceptable to use other vessels for calibrating EC, DO pH and ORP,
Turbidity
calibration should always be carried out in the purpose made bottles
, otherwise
accuracy can be seriously degraded.
10.2. Using RapidCal
RapidCal is an easy way to calibrate any of the Aquaprobes in the field using just one
calibration solution. RapidCal calibrates EC at 2570µS/cm, the pH7.00 point and the Zero
NTU Turbidity point simultaneously. Ideally, this procedure should be carried out at the
beginning of each day the Probe is to be used. To use RapidCal:
1. Remove the lid from a fresh 300mL bottle of RapidCal solution,
remove the storage cap from the pH electrode if fitted, wash the
Probe in distilled water, then drop the Probe in all the way. Bang
the Probe against the pad in the bottom of the bottle several
times in order to remove any air bubbles that may be clinging to
the Turbidity electrodes.
2. When the Probe is inserted,
ensure the level of the solution is
right up to the threaded part of the bottle.
If the level is low, as
shown in the photograph on the right, the EC electrodes will not
be covered and EC will not calibrate properly. If the level is low,
top up with fresh RapidCal solution.
3. Switch the Aquameter on and wait until the temperature, EC, pH
and Turbidity measurements are all
completely
stable. The
longer you can leave the probe to achieve thermal equilibrium
before proceeding, the better.
4. Ensure the temperature of the solution is between 5ºC and 40ºC (41ºF - 104ºF).
5. Press the
MENU
key then select
Calibration.
The following screen will be displayed.
© 2011 Aquaread Ltd.
www.aquaread.co.uk
Page 20 of 64
