1, tuning before the preparatory work:
1, to the mine scheduling telephone report, to obtain the consent of the mine scheduling before the start of tuning. (2), before the calibration, notify the monitoring room by phone, the sensor to be calibrated to change the name of the measurement point: "calibration", to be uploaded to the web page of the group company when the measurement point appears "calibration" before entering the next process.
(3) Put the gas cylinder vertically on the floor of the roadway (the flow control valve is facing upward, and the bottle is facing downward). (4) Take the sensor to be adjusted and put it down to the bottom plate of the roadway, check whether the appearance of the methane sensor is intact, and clean up the surface and the dust around the gas chamber, and open the air inlet cover to cover the sheet.
2, adjust the zero point: (1), the air bottle guide tube and sensor air chamber connection, pay attention to the connection to ensure that tight no air leakage. (2), with the remote control sensor to display "digital 1" file.
3, slowly open the air bottle switch, slowly adjust the flow rate adjustment valve, so that the cylinder pressure gauge shows the pressure value between 0 ~ 3 MPa. Then adjust the flow meter so that the flow rate is stabilized at 0.2L/min (low concentration sensor) or 0.1L/min (high and low concentration sensor) scale.
(4) Continuously pass into the air sample time is more than 90 seconds, until the sensor display value is stable before zeroing work.
(5), use the remote control to adjust the zero point, the zero value of the higher temperature location control at 0.02% CH4, the zero value of the lower temperature location control at 0.03% CH4, to prevent negative drift.
6, after the end of the zero adjustment, use the remote control to save the zero point, and then turn off the air bottle switch to ensure that the gate valve is closed tightly, and then ready to enter the next process, in the process, the air conduit to the sensor air chamber do not pull out.
3, adjust the accuracy:
1, test the alarm value and power-off value ①, with the remote control will be adjusted to display the sensor "digital 2" gear.
②, first slowly open the methane cylinder switch, so that the cylinder pressure gauge shows the pressure value between 0 and 3 MPa. Slowly adjust the flow control valve, first with a small flow to the sensor gas chamber slowly through the calibration gas samples, so that the sensor display value slowly rise, in the process, observe the alarm value and the power-off value is in line with the requirements, and pay attention to the sensor display value rises to the alarm value and the value of the power-off, whether or not to send out a sound and light alarm and whether or not the power is off on-site. ③, the alarm value and power-off value error does not exceed ± 0.05% CH4, if the excess is re-calibrated once, if the error of both exceeds ± 0.05% CH4, the sensor is replaced and re-calibrated.
⑵, calibration accuracy
Alarm value and power-off value after the completion of the test to adjust the flow rate to 0.2L/min (low-concentration sensors) or 0.1L/min (high and low concentration sensors) on the scale, for a period of time greater than 90 seconds, to be displayed by the sensor stabilizes the display value, record the display value, and then adjust the sensor display value with the remote control to the standard concentration of gas samples, and to make the Measured value is displayed stably for 60 seconds without change, then the remote control can be used to save the accuracy, the end of the tuning.
(3), test recharge function
After the end of tuning, slowly adjust the flow regulating valve, so that the sensor display value is less than the recharge value and continue to stabilize the gas for 60 seconds after closing the cylinder valve, and then close the flow regulating valve to end the test.
4, calibration accuracy value
After the completion of all the work of calibration in accordance with the "calibration accuracy" step requirements to re-fill the calibration gas samples on the accuracy value of the calibration, if the sensor displays a value of more than ± 0.05% CH4 range, it is necessary to replace the sensor, preheat the sensor and then re-tuning, until the sensor error meet the requirements.
5, adjust all the end of the school, re-check all the cylinders and flow meter gate valve is closed tightly, the air bottle and methane cylinder into the protective jacket, and then restore the sensor to work normally and according to the requirements of quality standardization to hang the sensor, check the tools, instruments intact, and finally to do the material site clear.