产品简介/Product introduction
井盖状态+可然气体智能监测终端包含井盖异动和可燃气体智能监测两部分，主要用来监测井盖状态是否正常以及井下是否存在可燃气体。产品安装在井盖下面，井盖以水平放置视为正常状态。
当井盖发生倾斜并达到触发报警条件（例如：倾斜角大于10°（倾角可设定）），或者井下可燃气体浓度超出设定阈值时触发报警。终端将报警信号通过无线传输方式发送至监控中心，监控中心对数据进行解析并判断警情。
该终端产品可提供NBIOT、LoRaWAN两种无线通讯方式。其使用电池供电，具有安装方便、电池寿命长、检测准确率高，工作稳定等特点。
The manhole cover status + recoverable gas intelligent monitoring terminal includes two parts: manhole cover transaction and combustible gas intelligent monitoring, which is mainly used to monitor whether the manhole cover status is normal and whether there is combustible gas underground. The product is installed under the manhole cover, and the manhole cover is placed horizontally as normal.
The alarm is triggered when the well cap tilts and meets the trigger alarm condition (for example, the inclination Angle is greater than 10° (the inclination Angle can be set)), or the downhole combustible gas concentration exceeds the set threshold. The terminal sends the alarm signal to the monitoring center through wireless transmission, and the monitoring center analyzes the data and judges the alarm.
The terminal product can provide NBIOT and LoRaWAN two wireless communication modes. It uses battery power supply, with easy installation, long battery life, high detection accuracy, stable work and so on.
工作原理/Working principle
井盖状态+可燃气体智能监测终端安装在井盖背面，终端通过加速度传感器测量井盖当前的倾斜角度，通过MEMS气体传感器监测可燃气体浓度。当该倾角值大于设定的报警值,或者可燃气体浓度超出阈值时触发报警（当倾角大于90°时，无条件报警），并通过无线网络将报警信息发送至监控中心。
终端支持设置定时上报时间间隔、报警角度阈值、气体采样时间间隔和气体报警浓度阈值等参数。非报警状态下，终端以定时上报时间间隔发送上报报文。在报警状态下，终端以立即发送上报报文，当恢复正常时，终端也会立即发送报文到平台。报文中的“设备状态”位用来指示当前的报警状态。“设备状态”位还可以指示当前的电量状态以及其他状态。
井盖异动的检测条件是：
| 井盖当前角度值 – 井盖背景角度值 | ＞ 报警角度阈值。
该条件满足时，发送报警信息。当倾角大于90°时，无条件报警。
有害气体报警的检测条件是：当前气体浓度 ＞ 气体报警浓度阈值。该条件满足时，发送报警信息。
The manhole cover status + Combustible gas intelligent monitoring terminal is installed on the back of the manhole cover. The terminal measures the current inclination Angle of the manhole cover through the acceleration sensor, and monitors the combustible gas concentration through the MEMS gas sensor. When the inclination value is greater than the set alarm value, or the combustible gas concentration exceeds the threshold, the alarm is triggered (when the inclination is greater than 90°, unconditional alarm), and the alarm information is sent to the monitoring center through the wireless network.
The terminal supports setting parameters such as periodic reporting interval, alarm Angle threshold, gas sampling interval, and gas alarm concentration threshold. In the non-alarm state, the terminal sends the reported packets at a periodic reporting interval. In the alarm state, the terminal will immediately send the report message, when the normal recovery, the terminal will immediately send the message to the platform. The "Device Status" bit in the message indicates the current alarm status. The "Device Status" bit can also indicate the current battery status and other states.
The detection conditions of manhole cover transaction are:
| current Angle value of manhole cover - background Angle value of manhole cover | > Alarm Angle threshold.
When this condition is met, alarm information is sent. When the Angle is greater than 90°, unconditional alarm.
The detection condition of harmful gas alarm is: the current gas concentration > the gas alarm concentration threshold. When this condition is met, alarm information is sent.
