MDR-3311超声波液位计

        一体型超声波液位仪可用于各种防爆领域的液位和测距等测控场合。由于一体型超声波液位仪为非接触式检测，较其它仪器更卫生，更耐潮湿、粉尘、高温、腐蚀气体等恶劣环境(特指全密封型传感器)，具有少维护、无污染、高可靠、长寿命等特点，因此广泛应用于石油、纸业、矿业、电厂、化工业、水处理、废水净化、制药厂、农业抽水、环保监测、污水处理、食品(酿酒业、饮料业、添加剂、食用油、奶制品)等行业及防爆环境的液位、料位测量，还可应用于工业领域中的堆放厚度、高度、张力、直径、运动目标空中定位测控，以及防汛、水文、明渠流量变送器、铁路、公路限高、集装箱码头、飞机场等行业中。

        A type ultrasonic level meter can be used in various explosion-proof fields such as liquid level and distance measurement and control occasions. Because the ultrasonic level meter is a non-contact detection, it is more sanitary than other instruments, more resistant to harsh environments such as moisture, dust, high temperature, corrosive gas (especially the fully sealed sensor), with less maintenance, no pollution, high reliability, long life and so on. Therefore, it is widely used in petroleum, paper industry, mining industry, power plant, chemical industry, water treatment, wastewater purification, pharmaceutical factory, agricultural pumping, environmental monitoring, sewage treatment, food (brewing industry, beverage industry, additives, edible oil, dairy products) and other industries and explosion-proof environment liquid level and material level measurement. It can also be used in the industrial field of stacking thickness, height, tension, diameter, moving target air positioning measurement and control, as well as flood control, hydrology, open channel flow transmitter, railway, highway height limit, container terminal, airport and other industries.
MDR-3311超声波液位计工作原理/Ultrasonic liquid level meter working principle:
        超声波液位计工作原理是由超声波换能器（探头）发出高频脉冲声波遇到被测物位（物料）表面被反射折回反射回波被换能器接收转换成电信号。声波的传播时间与声波的发出到物体表面的距离成正比。声波传输距离S与声速C和声传输时间T的关系可用公式表示：S=C×T/2。

        由于发射的超声波脉冲有一定的宽度，使得距离换能器较近的小段区域内的反射波与发射波重迭，无法识别，不能测量其距离值。这个区域称为测量盲区。盲区的大小与超声波物位计的型号有关。

        探头部分发射出超声波，超声波遇到与空气密度相差较大的介质会行成反射，反射波被探头部分再接收，探头到液（物）面的距离和超声波经过的时间成比例：

        距离 [m] = 时间×声速/2 [m]

        声速的温度补偿公式：环境声速= 331.5 + 0.6×温度
        The working principle of the ultrasonic level meter is that the ultrasonic transducer (probe) emits high-frequency pulse sound waves when the surface of the measured object (material) is reflected back and the reflected echo is received by the transducer and converted into an electrical signal. The travel time of the sound wave is proportional to the distance of the sound wave to the surface of the object. The relationship between acoustic transmission distance S and sound speed C and sound transmission time T can be expressed by the formula: S=C×T/2.

        Because the emitted ultrasonic pulse has a certain width, the reflected wave and the emitted wave in the small segment close to the transducer overlap, which cannot be identified and its distance value can not be measured. This area is called the measurement dead zone. The size of the blind area is related to the model of the ultrasonic level meter.

The probe part emits the ultrasonic wave, the ultrasonic wave meets the medium with a large difference in air density will be reflected, and the reflected wave is received by the probe part, the distance of the probe to the liquid (material) surface is proportional to the time of the ultrasonic wave:

        Distance [m] = Time × speed of sound /2 [m]

        Temperature compensation formula of sound velocity: ambient sound velocity = 331.5 + 0.6× temperature
MDR-3311超声波液位计安装方式/Ultrasonic liquid level meter Installation mode:

        敞开环境下一般采用支架安装方式，用仪表自带法兰或螺母固定。池或罐在安装位置上割一个略大于探头直径（60mm）的圆孔，将仪表放入，然后将法兰或螺母自下而上旋紧。安装必须保证仪表的探头面与被测液面水平。常见有以下三种安装方式可供选择。
        In an open environment, a bracket is generally installed and fixed with the flange or nut delivered with the instrument. Cut a round hole slightly larger than the diameter of the probe (60mm) in the mounting position, place the meter in, and tighten the flange or nut from bottom to top. Installation must ensure that the probe surface of the instrument is level with the measured liquid level. The following three installation methods are available.

MDR-3311超声波液位计性能特点/Ultrasonic liquid level meter Performance characteristics:

        抗干扰性强。可任意设置上下限节点及在线输出调节，并带有现场显示，可选择模拟量，开关量及RS485输出，方便的与相关设施接口。

        坚固防水外壳。壳体小巧且相当坚固，具有优良的耐化学品性，对于无机化合物，不论酸、碱、盐溶液，除强氧化性物料外，几乎都对其无破坏作用，对几乎所有溶剂在室温下均不溶解，一般烷、烃、醇、酚、醛、酮类等介质上均可使用。

        无毒性。可用于药品、食品工业设备安装，维修极为方便。

        Strong anti-interference. Can set the upper and lower limit nodes and online output adjustment, and with field display, can choose analog, switching and RS485 output, convenient interface with related facilities.

        Strong waterproof housing. The shell is small and quite strong, with excellent chemical resistance, for inorganic compounds, regardless of acid, alkali, salt solution, in addition to strong oxidizing materials, almost have no destructive effect on it, almost all solvents are insoluble at room temperature, generally alkanes, hydrocarbons, alcohols, phenols, aldehydes, ketones and other media can be used.

        Non-toxic. Can be used for medicine, food industry equipment installation, maintenance is very convenient.

MDR-3311超声波液位计技术参数/Ultrasonic liquid level meter technical parameters:
测量范围/Measuring range：5m、10m、15m、20m、25m（根据实测量程选定）

盲区/Blind area：0.25m～0.6m

测距精度/Ranging accuracy：0.25%～0.5%（标准条件）

测距分辨率/Ranging resolution：1mm

压 力/Pressure：4个大气压以下

仪表显示/Instrument display：自带LCD显示液位或空间距离

模拟输出/Analog output：4～20mA

数字输出/Digital output：RS485 / Modbus协议或定制协议

供电电压/Power supply voltage：DC12V / DC24V / AC220V，防雷装置内置

环境温度/Ambient temperature：－20℃ ～ ＋60℃（高温定制请说明）

防护等级/Protection level：IP65 / IP68

MDR-3311超声波液位计结构外观及接口说明/Ultrasonic liquid level meter structure appearance and interface description：

                                       （探头可按需定制）                                                                         （安装原理示意图）