Teledyne BDS-3960 operating instructions Alarms Function

Oxygen Analyzer Maintenance

4.4.2.1SPAN FAILURE

The analyzer checks the output of the cell at the end of the span. If the raw output of the cell is less than 1.5 nA/ppb or more than 13.5 nA/ppb O2, the span will not be accepted. The analyzer will return to the previous calibration values, and display at the top of the main screen:

SPAN-CALIBRATION

ERROR

4.5The Alarms Function

The Model BDS 3960 is equipped with 2 fully adjustable concentration 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 VAC. 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 PPC software 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.

Depending on your process, you can choose to configure the alarms in a number of ways. 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:

•Both high (high and high-high) alarms, or

•One high and one low alarm, or

•Both low (low and low-low) alarms.

Teledyne Analytical Instruments 51