Sierra Monitor Corporation 4501-06, 4501-XX Calibration Procedure, Model, Flow, Period, Page

Model 4501-XX Toxic Gas Sensor Module

6. CALIBRATION

6.1CALIBRATION FREQUENCY

The sensor module must be calibrated every 180 days. Periodic functional tests are advisable for critical applications and hostile environments.

The sensor module microprocessor software includes high-level self checking algorithms which provide continuous sensor diagnostic and self adjustment.

6.2CALIBRATION PREPARATION

Calibration of the sensor is accomplished by simple menu based steps and application of span gas.

NOTE

If an error is made during any stage of the calibration process, hold the magnet stick at the [M] for 10 seconds. A scrolling display will indicate “Operate Mode” and the sensor module will exit the calibration activity and return to normal operating mode. The calibration procedure can then be restarted.

Calibration must be performed only when the area is known to be clear of Hydrogen Sulfide gas. When in doubt, use a portable instrument to confirm that there is no background Hydrogen Sulfide gas.

For compliance with Factory Mutual (FM) Approvals, the Sierra Monitor Model 1250-01, 1260 -05 and 1260-45 are the FM Approved calibration gas delivery devices. Use the Model 5358-01 Calibration Adapter delivery fitting.

6.2.1 CALIBRATION GAS DELIVERY METHODS

Calibration gas can be delivered to the sensors via the Model 5358-01: Calibration Adapter (Figure 6-1) - used with portable calibrators.

CALIBRATION PROCEDURE

The Calibration Menu is described on Table 6-1:

The procedure requires that the menu “keys” be activated using the magnet stick. Each key press steps through the process of setting the zero value for clean air and then setting the span value.

At each of these steps, apply calibration gas of the value corresponding to the setting accepted on the sensor module display.

6.2.2 SENSOR EXPOSURE TO GAS

Calibration gas must be delivered to the sensor using the flow rate and duration listed in below:

Model	Gas	Flow	Period
4501-04	Carbon Monoxide	300 cc/min	Until Stable (minimum 3 minutes)
4501-05	Hydrogen Sulfide	300 cc/min	Until Stable (minimum 3 minutes)
4501-06	Chlorine	300 cc/min	Until Stable (minimum 3 minutes)

Sample Gas In

Figure 6-1

Model 5358-01

Calibration Adapter

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