Teledyne 3000TA-XL-EU operating instructions Alarms Function, Special Notes on Hydrogen Gas Stream

Trace Oxygen Analyzer Operation 4

nitrogen and helium will not require SPAN adjustment. However, care must be taken to keep sample flow rates in the desired levels, as the flowmeter is calibrated for air and nitrogen streams only.

3.The analyzer can withstand repeated switching of streams between low oxygen levels of less than 1 ppm and high oxygen levels of 5000 to 10,000 ppm. Again, care must be taken to ensure proper and continuous flows at all times.

4.5.1Special Notes on Hydrogen Gas Stream

The standard oxygen cell, Model B-2CXL, though tested in nitrogen gas streams is expected to perform well in hydrogen streams. Hovewer, for certain applications such as continuous monitoring of very low levels of oxygen in hydrogen, the user may request cells that have been specifically tested in hydrogen streams. Consult Teledyne for further details.

4.6The Alarms Function

The Model 3000TA-XL is equipped with 2 fully adjustable concentra- tion alarms and a system failure alarm. Each alarm has a relay with a set of form “C" contacts rated for 3 amperes resistive load at 250 V ac. See Figure 3-5 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 as 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 oxygen concentration rises above the setpoint. Setting an alarm as LOW triggers the alarm when the oxygen concentration falls below the setpoint.

Decide whether you want the alarms to be set as:

Teledyne Analytical Instruments 4-17