Model 420 & 425 Flame Photometer
425 91 001
Issue 22
1
st
December 2016
ECN 1410 & 1932
- 41 -
Description of Instrument
continued
5.3
Operating Modes
continued
5.3.2 Peak/Cont
Refer to Section 5.1.1 for the function of the ‘Peak/Cont’ button and to Section 5.1.2
for its status indicators ‘Peak/Ref/Cont’.
Peak
This mode is intended to give the user a frozen measurement value on the
instrument display. This not only removes subjectivity form the user but also offers a
much greater advantage by enabling automation of sample delivery and collection of
results.
The Peak Cycle
The full sequence of the peak process is as follows: -
The cycle commences with the introduction of a new sample, quickly followed by
pressing 'Measure'.
The instrument starts a built-in delay (which can be varied see Section 2.9) as soon
as a press of 'Measure' has been registered, (whether a short, long or double press
does not matter); readings are displayed on all operative channels. When the values
satisfy the peak detection algorithm the display(s) freeze and the "Measure" indicator
will become steady. A single beep will sound and a valid measurement value will be
output to the RS232 serial port.
The cycle cannot re-commence until the previous values flash and the measure
indicator is steady.
Then a new sample can be aspirated and “Measure” is pressed.
If the cycle has timed out for the previous sample before the algorithm was
successful on all operative channels, "measure" will flash and "E22" will be showing
on at least one display.
(
NB
a full list of all codes is printed as Appendix B).
