Hach BioTector B3500s, User Manual

Page: 43 / 166

Page 43
4.2.2 BioTector Sample Injection
The BioTector analyzes a precise volume of liquid. The Sample Pump injects a pre-programmed number of
pulses (half revolutions of pump) of liquid into the reactor for each measurement and therefore the volume of
liquid included in each pulse is consistent.
Sample is initially drawn from the source by a peristaltic Sample Pump.
In standard TIC & TOC systems, Acid Pump activates and the first TIC acid is injected into the Mixer Reactor.
Sample Valve and Reactor Valve activates, Sample Pump rotates forward and injects the sample directly into
the Mixer Reactor with the relevant number of pulses appropriate to the range.
In TC systems, the sample injection is carried out similar to the one described for TIC & TOC systems above
but unlike TIC acid, first the base reagent (e.g. Sodium Hydroxide) is injected into Mixer Reactor. Sample
Valve and Reactor Valve activates, Sample Pump rotates forward and injects the sample directly into the
Mixer Reactor with the relevant number of pulses appropriate to the range.
In VOC systems, BioTector carries out two separate sample injections for the two analysis reactions run
consecutively in a single reactor configuration. The first analysis reaction is a TC reaction and the second one
is a TIC & TOC reaction. The sample injection takes place as described for the TC systems and for the TIC &
TOC systems above. Figure 4 shows the typical analysis layout of TIC & TOC system below.
Detailed information on sample injection is available, in presentation and video formats, in the MMC/SD card
shipped with the BioTector. It is recommended to review these files to understand BioTector sample injection.