HF scientific 19998 Triple Validation Turbidimeter - 0-100 NTU - Manual (Page 15)

TVT 1 (5/02) 9
Rev. 2.6 (.pdf)
4.1 Routine Measurement
The following steps describe how to measure the turbidity of a sample using this
instrument:
1. Apply power to the instrument and allow the unit to warm up (typically 45 minutes –
1 hour on initial commissioning).
2. When a continuous process stream is flowing through the instrument, the instrument
will display the measured turbidity level of the sample by displaying it on the LCD
screen. In addition, the equivalent signal is provided on the analog output and the
timed digital output (if selected).
4.2 Security Access Feature
The instrument is equipped with a security access code feature that can be activated in the
configuration mode. If the security feature is enabled, the screen shown in the illustration
below will appear when you press the MODE button.
The security code has three numbers that are selectable one at a time. Notice that the first
number in the code is flashing; the flashing indicates that this is the number to be
changed. Use the
tor u arrows to select the value of the first number in the code and
then press the
↵ ↵↵ ↵
button to accept the first number of the code. After you have pressed
enter, the second number in the code will start to flash. Proceed as with the first number.
Then repeat the process for the third number in the access code.
If you have selected a valid access code, the instrument will be directed to either the
calibration or the user setup mode depending on the access code that was provided to the
instrument. If the wrong access code is selected, the instrument will return to the AUTO
mode.
Note: Only three access codes are used in the instrument: one for instrument calibration
(333), on for calibration by comparison/offset (555) and one for instrument
configuration (444); these codes are not programmable.
5.0 Instrument Calibration
The instrument was calibrated and tested prior to leaving the factory. Therefore, it is
possible to use the instrument directly out of the box. However, re-calibration of the
instrument is recommended to help you become familiar with the operation of the