Teledyne 2010A - Split architecture thermal conductivity analyzer - Manual (Page 50)

4 Operation Model 2010A
4-16 Part I Teledyne Analytical Instruments
units, as necessary. When you have set the concentration of the span gas you are
using, press
Enter to begin the Span calibration.
Press Enter to enter the span value into the system and begin the span
calibration.
Once the span has begun, the microprocessor samples the output at a
predetermined rate. It calculates the difference between successive samplings
and displays this difference as Slope on the screen. It takes several seconds for
the first Slope value to display. Slope indicates rate of change of the Span
reading. It is a sensitive indicator of stability.
####.##% H2 — N2
Slope=#.### Span
When the Span value displayed on the screen is sufficiently stable, press
Enter . (Generally, when the Span reading changes by 1 % or less of the range
being calibrated for a period of ten minutes it is sufficiently stable.) Once Enter
is pressed, the Span reading changes to the correct value. The instrument then
automatically enters the
Analyze function.
4.5 The Alarms Function
The Model 2010A is equipped with 6 fully adjustable set points concentra-
tion with two alarms and a system failure alarm relay. Each alarm relay has a set
of form “C" contacts rated for 3 amperes resistive load at 250 V ac. See Figure
in Chapter 3, Installation and/or the Interconnection Diagram included at the
back of this manual for relay terminal connections.
The system failure alarm has a fixed configuration described in chapter 3
Installation.
The concentration alarms can be configured from the front panel as either
high or low alarms by the operator. The alarm modes can be set as latching or
non-latching, and either failsafe or non-failsafe, or, they can be defeated
altogether. The setpoints for the alarms are also established using this function.
Decide how your alarms should be configured. The choice will depend
upon your process. Consider the following four points:
1. Which if any of the alarms are to be high alarms and which if any
are to be low alarms?
Setting an alarm as HIGH triggers the alarm when the
contaminant concentration rises above the setpoint. Setting an
alarm as LOW triggers the alarm when the contaminant
concentration falls below the setpoint.
Decide whether you want the alarms to be set as: