Guildline Autosal 8400B - 6. OPERATING INSTRUCTIONS; 6.1. GENERAL; 6.2. OPERATING SEQUENCE; 6.2.1. CHECKING ZERO REFERENCE

Section 6
TM8400B-L-00
1 November 2004
6-1
6. OPERATING INSTRUCTIONS
6.1. GENERAL
The instrument operating sequence entails:
(a) Checking the instrument zero reference to ensure the instrument is properly calibrated.
(b) Standardizing the instrument to standard sea-water, or checking to ensure previous
standardization is still valid.
(c) Measuring the 2 times conductivity ratio of the sample water.
(d) Converting the instrument reading to equivalent salinity of the sample.
A properly calibrated instrument will remain standardized provided:
(a) STANDARDIZE control remains unchanged.
(b) TEMPERATURE - °C setting remains unchanged.
(c) Room temperature is within -4°C and +2°C of TEMPERATURE °C setting.
This section includes recommended standard practices associated with the instrument operating
sequence. It also describes the techniques for precision measurement.
Before using the instrument and periodically during its use, always routinely check the
instrument to ensure the zero reference or calibration has not drifted. If the instrument has been
in storage or out of service, refer to Section 5 and to the appropriate installation checks.
6.2. OPERATING SEQUENCE
6.2.1. CHECKING ZERO REFERENCE
(a) Ensure instrument is powered up per Section 5.2.
(b) Select FUNCTION switch to ZERO.
(c) Check last four digits of display read 0000 (last digit ±5); instruments
whose reading does not conform to this check specification require
recalibration as described in the service manual. Note that the stability
of this number over time is of more significance than it's actual value.