Emerson MA N-00 05-00, UT-P+-STXXXX user manual Magnetic Reed Switch Activation

It is necessary to calibrate the UNI-TRAN Premium Plus when it is used as a stand-alone device and connected to other monitoring equipment requiring a precise 4 to 20mA output signal. The following calibration procedure should be followed to ensure an accurate correlation between the 4 to 20mA output signal and the sensor input signal.

Calibration Procedure for UNI-TRAN Premium Plus (not applicable for ST1400 O2 sensor, refer to the end of this procedure)

<Confirm that the system is powered-up and is not indicating a fault; Status LED is showing a green blip every 2.0 seconds.

<Ensure that the sensor is in a clean air environment before beginning the calibration procedure or we recommended to flow certified ZERO AIR at a rate of 0.5 litres per minute through the barbed tubing connector on the end of the sensor calibration cup accessory, for one minute to ensure clean air is present. If the input device is another transmitter be sure that it is calibrated and that the input to the Toxic Detector is 4.0mA.

<Enter the main menu by activating the magnetic reed switch or manual push button switch. When the countdown from 10 to 0 is complete remove the magnet from the magnetic reed switch or release the CAL/RESET push button. When prompted with Calibrate sensor “YES?” select the function by momentarily placing the magnet on the reed switch or depressing the CAL/RESET button. The selection is acknowledged with flashing “YES”. The controller starts calibration. The following Instructions are scrolled across the display for calibration:

Setting Zero - At this time input should be 4.0mA or ZERO gas applied to the sensor (3.0mA output current level).

Apply 50 % Span - at this time input should be 12.0mA or apply 50% span gas at a rate of 0.5 litres per minute to the end of the sensor calibration cup accessory (3.3mA output current level).

Figure 17 - Magnetic Reed Switch

Activation

Setting Span - increasing input signal has been detected (3.3mA output current level).

Remove Gas - at this time input should be reduced to 4.0mA by removing span gas from the sensor (3.6mA output current level).

Cal Complete - Returns to normal operation (4.0mA output current)

NOTE:

If span setting does not complete successfully within ten minutes of starting the calibration sequence the status LED alternates flashes of RED and GREEN, the analog output changes back and forth from 3.0 to 3.3mA and Fail Cal. message is displayed on the screen. The unit remains in this state until acknowledged by a manual Reset. After manual Reset the program will return to the normal operation mode using previous calibration values. Since the calibration was unsuccessful another attempt may be made or replace the sensor and re-try calibration.

25