Teledyne 6600 - Manual (Page 98)

1-8 Part III
Part III Model 6600
Teledyne Analytical Instruments
sample (selected for total oil or non-dissolved oil applications based upon
valve V4 position).
The zero water may be supplied to the measuring cell by the existing process
available pressure, by a user gravity feed system or by a pump (user supplied
at the take-off) or by TAI either remotely at the takeoff source or within the
analyzer sampling system. Normal measuring mode flowrates (commonly
are 100-1000 liter/minute) will render response times of under 10 seconds
typically for 90% FSD (this does not include any lag-time associated by the
fast loop in the system). Each system may be slightly different depending
upon components used (see B71046 piping), but generally the system is
quite fast and many times can be tailored to meet fast response requirements.
The 6600 timer will now activate the auto zero circuit and correct the meter
and recorder to read the zero level previously set to the true absolute zero for
the process fluid.
If the output of the subtractor remains as it was on the preceding zero cycle,
then no correction of the auto zero circuit is required. This means that no
background change has occurred during the past hour.
When the output of the subtractor is other than the previous zero cycle
value, the Auto Zero circuit would compensate for the difference, resulting in
zero volts at its output. This zero voltage, applied to the input of the Sample and
Hold/Buffer circuitry.
The 6600 then (optionally) can insert a manual or automatic employed span
flag that simulates an upscale reproducible calibration analyte of interest.
This function adds another 10-20 seconds to the zero/span check/correc-
tion.
After auto zero/span is taken all solenoid valves are de-energized with the
following consequences:
1. The sample is delivered to the sample cell for the next 55 min. The
instrument has returned to the sample cycle and the analyzer monitors
the sample for oil.
3.0 System Description
The oil-in-water analyzer is generally constructed as either an explosion-proof
6600Z or X Purge or general-purpose (Model 6600) unit, open rack or closed
cubicle mounted. An equipment panel is used to support the analyzer components.