浮球液位计和超声波液位计的比照剖析

 一、丈量比拟：

 ①浮球液位计是做一个空心球，漂在液面位置，再用各种 或机械 或电子 或用球带动其它安装 的手腕检测这个球的位置，来检测液位。

 ②超声波液位计是对着液面发射超声波，并检测反射到接纳器的时间，从而判别液位上下。

二、原理比拟：

 ①浮球液位计采用连通器的原理。使容器内液体等高引入到液位计主体管内。在主体管内的漂浮浮球组件，依据浮力原理和磁性藕合原理。在主体管外附靠着能反映磁现象的翻柱作为液面位置的显现。随文体管内液位的变化，浮球组件的上下也相应变化。从而使主体管外的翻柱作180度的翻转，当液位上升时，翻柱由白色转为红色，当液面降落时，翻柱由红色转为白色。显现器的红，白界位处为容器内介质液位的实践高度。

 ②超声波液位计的工作原理是由换能器（探头）发出高频超声波脉冲遇到被测介质外表被反射回来，局部反射回波被同一换能器接纳，转换成电信号。超声波脉冲以声波速度传播，从发射到接纳到超声波脉冲所需时间距离与换能器到被测介质外表的间隔成正比。此间隔值S与声速C和传输时间T之间的关系能够用公式表示：S=CxT/2。由于发射的超声波脉冲有一定的宽度，使得间隔换能器较近的小段区域内的反射波与发射波重迭，无法辨认，不能丈量其间隔值。这个区域称为丈量盲区。盲区的大小与超声波物位计的型号有关。

三、特性比拟：

 ①适用于容器内液体介质的液位丈量除现场显现外，还可配远传变送器、液位控制器等功用，显现直观醒目，显现方向可依据用户请求改动显现万向，丈量范围大，不受容器高度限制，显现器组件与被测介质完整隔离，故密封性好牢靠平安，构造简单，装置万便，维修简易，耐腐蚀、防爆。

 ②超声波液位计采用了先进的微处置器和共同的EchoDiscovery回波处置技术，超声波物位计能够适用于各种复杂工况。换能器内置温度传感器，可完成丈量值的温度补偿，使其发射功率能更有效地辐射进来，进步信号强度，从而完成精确丈量。

四、装置留意点：

 ①浮球液位计浮球和导杆间不能有杂物，防止导杆溅上杂物，抗介质活动的才能较小，装置定位时要留意防止。浮球上下运动时不能有障碍。在介质存在活动时要避开急流装置，必要时可增强导杆固定或加装静止套。

 ②超声波液位计最高料位不得进入丈量盲区；仪表距罐壁必需坚持一定的间隔；两者液位计在装置时都需留意装置垂直度契合请求，超声波液位计尽可能使换能器的发射方向与液面垂直。

Comparative analysis of float ball level gauge and ultrasonic level gauge

I. measurement comparison:

(1) float ball liquid level meter is to do a hollow ball, floating in the liquid level position, and then with a variety of mechanical or electronic or ball to drive other installed wrist detection of the ball position, to detect the liquid level.

(2) ultrasonic liquid level meter is against the liquid surface emission ultrasonic, and detect the reflection to the acceptor time, so as to distinguish the liquid level up and down.

Ii. Principle comparison:

(1) float ball liquid level meter using the principle of communicator. The liquid in the container is introduced into the main tube of the level gauge at the same height. The floating ball assembly in the main tube is based on buoyancy principle and magnetic coupling principle. Outside the main tube is attached to the inverted column which can reflect the magnetic phenomenon as the position of liquid level. With the change of fluid level in the tube, the up and down of the floating ball components also change accordingly. As a result, the inverted column outside the main pipe is turned 180 degrees. When the liquid level rises, the inverted column turns from white to red, and when the liquid level falls, the inverted column turns from red to white. The red and white boundary of the display device is the practical height of the medium level in the container.

(2) the working principle of ultrasonic liquid level meter is by the transducer (probe) sent out high frequency ultrasonic pulse encountered measured medium surface is reflected back, local reflection echo is accepted by the same transducer, converted into electrical signals. The ultrasonic pulse travels at the speed of sound waves, and the distance from transmission to acceptance to the ultrasonic pulse is proportional to the distance between the transducer and the appearance of the medium under test. The relationship between this interval value S, sound velocity C and transmission time T can be expressed by the formula: S=CxT/2. Because the transmitted ultrasonic pulse has a certain width, the reflected wave and transmitted wave overlap in the small area near the interval transducer, making it unrecognizable and impossible to measure the interval value. This area is called the measurement blind area. The size of the blind area is related to the type of ultrasonic level meter.

Iii. Comparison of characteristics:

(1) is suitable for the container liquid level measurement of liquid medium in addition to the live show, also can match remote transmitter, liquid level controller, such as function, displayed visually striking, show the direction can be based on user requests changes show universal, wide measurement range, without being limited by the height of container, components and the complete isolation of measured medium, so the sealing good secure peace, simple structure, device then, easy maintenance, corrosion resistance, explosion-proof.

(2) ultrasonic liquid level meter adopts advanced micro disposal device and common EchoDiscovery echo disposal technology, ultrasonic level meter can be applied to a variety of complex conditions. The built-in temperature sensor of the transducer can compensate the temperature of the measured value, so that the transmitted power can be radiated in more effectively and the signal strength can be improved, so as to complete the accurate measurement.

Iv. Device attention points:

(1) float ball liquid level gauge float ball and guide bar can not be sundry, prevent guide bar splash sundry, anti medium activity ability is small, the device should pay attention to prevent positioning. There must be no obstruction to the movement of the float up and down. When the medium is active, the jet stream device should be avoided. When necessary, the guide rod can be strengthened and fixed or static sleeve can be added.

(2) ultrasonic liquid level meter the highest material level can not enter the measurement blind area; Instrument distance from tank wall must adhere to a certain interval; Both liquid level meters should pay attention to the request of fitting the perpendicularity of the device when the device is installed. Ultrasonic liquid level meter should make the transmitting direction of the transducer perpendicular to the liquid level as far as possible.