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Version 14.13 by Edwin Chen on 2025/06/25 09:27
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1 **~ Table of Contents：**
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3 {{toc/}}
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7 = 1. Overview =
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10 This URL introduce different methods to detect the water / liquid level.
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13 = 2. Flow switch =
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15 == 2.1 How it works ==
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18 Below is an example of flow switch. and product link:
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20 [[https:~~/~~/www.amazon.com/Float-Switch-Septic-System-Sump/dp/B0064BHEVM/ref=sr_1_5?crid=2PCMSD63FBP42&keywords=float%2Bswitch&qid=1671230997&refinements=p_72%3A1248909011&rnid=1248907011&s=hi&sprefix=float%2Bswitch%2Caps%2C155&sr=1-5&th=1 >>https://www.amazon.com/Float-Switch-Septic-System-Sump/dp/B0064BHEVM/ref=sr_1_5?crid=2PCMSD63FBP42&keywords=float%2Bswitch&qid=1671230997&refinements=p_72%3A1248909011&rnid=1248907011&s=hi&sprefix=float%2Bswitch%2Caps%2C155&sr=1-5&th=1]]
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22 [[image:image-20221217164157-1.png||height="329" width="486"]]
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25 [[image:image-20221217164432-3.png||height="282" width="501"]][[image:image-20221217164337-2.png||height="279" width="431"]]
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27 The switch will switch on/off to show if the water / liquid has dedicate level.
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30 To use such switch with Dragino Products, use can connect it to LSN50v2 use the same way as a door switch. See reference link:
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32 [[http:~~/~~/wiki.dragino.com/xwiki/bin/view/Main/User%20Manual%20for%20LoRaWAN%20End%20Nodes/LSN50%20%26%20LSN50-V2%20-%20LoRaWAN%20Sensor%20Node%20User%20Manual/#H2.4.5DigitalInterrupt >>http://wiki.dragino.com/xwiki/bin/view/Main/User%20Manual%20for%20LoRaWAN%20End%20Nodes/LSN50%20%26%20LSN50-V2%20-%20LoRaWAN%20Sensor%20Node%20User%20Manual/#H2.4.5DigitalInterrupt]]
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34
35 == 2.2 Advantage & Disadvantage ==
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38 (% style="color:blue" %)**Advantage**(%%) : Reliable , Easy to install & Immue to different environment.
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40 (% style="color:red" %)**Disadvantage**(%%): Only be able to detect one speicify level. Not able to detect full range of water.
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42
43 = 3. Ultrasonic Sensor / LiDAR Sensor / Microwave Ridar =
44
45 == 3.1 How it works? ==
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47 These type sensors normally install on the top of the liquid leve and use different technology (Ultrasonic/ LiDAR ToF / MicroWave Ridar) to check the l
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49 Such as [[LDDS75>>https://www.dragino.com/products/distance-level-sensor/item/161-ldds75.html]] / [[LDDS45>>https://www.dragino.com/products/distance-level-sensor/item/191-ldds45.html]]. They are using ultrasonic technologic to detect the distance between the probe and a flat object such as water level.
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51 Below is photo and URL shows how Ultrasonic Sensor works to detect Water Level
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53 [[https:~~/~~/www.electricalvolt.com/2022/06/ultrasonic-level-transmitter-working/ >>https://www.electricalvolt.com/2022/06/ultrasonic-level-transmitter-working/]]
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55 [[image:image-20221217170756-1.png||height="465" width="539"]]
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58 When choose the ultrasonic sensor, we need to check the measure range , blind spot and angel to fit the tank.
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60 An important notice, if there are moisture accumulated in the sense area of Ultrasonic Probe of LDDS75/LDDS45. the reading will become invalid.
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62
63 == 3.2 Advantage & Disadvantage ==
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66 (% style="color:blue" %)**Advantage**(%%) :  Able to detect the level. Good Accurancy.
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68 (% style="color:red" %)**Disadvanage**(%%): Wrong reading when probe is block by moisture or other stuff. Affect by temperature.
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70
71 = 4. Pressure Sensor =
72
73 == 4.1 How it works? ==
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76 Pressure Sensor such as [[PS-LB>>https://www.dropbox.com/sh/eshhuk347xi1ce4/AAA4LUmYc2ITayfJUVsqK3wya?dl=0]] measures the pressure of the air / gas / liquid so can calcualte the liquid level.
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78 there are two types , (% style="color:blue" %)**Thread type** (%%)and (% style="color:blue" %)**Immersion type**(%%). as below:
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81 [[image:image-20221228143643-1.png||height="223" width="312"]] [[image:image-20221228144206-2.png||height="256" width="335"]]
82
83
84 == 4.2 Advantage & Disadvantage ==
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86
87 (% style="color:blue" %)**Advantage**(%%) :  Able to detect air / gas / liquid pressure level. Immue to factors such as moisture / blocking. etc. Flexible for installation for
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89 (% style="color:red" %)**Disadvanage **(%%): When use Thread Type sensor, make a hole on the tank is a challenge and when measure different Liquid, system intergrator need to calculate the level / pressure mapping, because different liquid has different density.
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