TM8400B-L-00
1 November 2004
(k) With FUNCTION switch set to STANDBY, record last four digits of
display.
NOTE: These four digits are used as a standardization indicator.
If these four digits change to a different reading with FUNCTION
switch on STANDBY the instrument has electrically shifted.
Restandardize as above when change in displayed value is greater
than ±5 last digits.
6.2.3. SAMPLE MEASURING PROCEDURE
NOTE: Samples up to 15 °C below the bath temperature can be measured if the
flow rate is reduced sufficiently to allow the sample to reach the bath temperature
while in the heat exchanger; however, this practice may not give the most accurate
results obtainable. All conductivity measurements are made with the
TEMPERATURE SENSOR switch in the NORMAL position.
Step 1. Install sample bottle as follows:
(a) Check and record sample bottle identity.
(b) Thoroughly, but gently, agitate to eliminate gradients.
(c) Open bottle and place in holder, inserting pick-up tube into bottle neck
and bottle mouth over rubber seal. Ensure pick-up tube reaches almost
to bottom of bottle but not touching such as to restrict flow.
(d) Adjust and secure platform to ensure airtight seal.
NOTE: The importance of purity of a sample cannot be
overstressed. Do not handle the pick-up tube, rubber seal or neck
of bottle except with clean tissue for wiping or surgical gloves for
handling.
Step 2. Turn on pumps and allow conductivity cell to fill with sample water, adjusting
FLOW RATE valve for medium flow rate.
Step 3. Flush sample water out of cell by placing fingertip over FLUSH air vent.
Step 4. Fill and flush two more times, using FLUSH air vent control, while adjusting
flow rate to suit sample temperature.
NOTE: A flow rate which is too fast is indicated by a marked change in
the on/off cycle of the heater lamps. Slowly reduce the flow rate until the
heater lamps cycle normally.
To Next Page
Loading...