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Last modified by Edwin Chen on 2025/06/26 11:53
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1 **~ Table of Contents：**
2
3 {{toc/}}
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5
6
7 = 1. Overview =
8
9
10 This URL introduce different methods to detect the water / liquid level.
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12
13 = 2. Flow switch =
14
15 == 2.1 How it works ==
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17
18 Below is an example of flow switch. and product link:
19
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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37
38 (% style="color:blue" %)**Advantage**(%%) : Reliable , Easy to install & Immue to different environment.
39
40 (% style="color:red" %)**Disadvantage**(%%): Only be able to detect one speicify level. Not able to detect full range of water.
41
42
43 = 3. Ultrasonic Sensor / LiDAR Sensor / Microwave Ridar =
44
45 == 3.1 How it works? ==
46
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 liquid level.
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49
50 For example: [[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]] are using ultrasonic technologic to detect the distance between the probe and a flat object such as water level.
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52 Below is photo and URL shows how Ultrasonic Sensor works to detect Water Level. LiDAR ToF and MicroWave RiDar are similiar.
53
54 [[https:~~/~~/www.electricalvolt.com/2022/06/ultrasonic-level-transmitter-working/ >>https://www.electricalvolt.com/2022/06/ultrasonic-level-transmitter-working/]]
55
56 [[image:image-20221217170756-1.png||height="465" width="539"]]
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58
59 When choose the these sensors, the consideration are:
60
61 * If the measure range , blind spot and angel fit the tank installation and measurement requirement.
62 * Make sure the liquid on the tank will not touch the top so touch the sensor.
63 * If there are moisture or dust accumulated in the sense area of probe of Ultrosonic Sensor or LiDAR ToF. the reading will become invalid. In this case, a Auto-Clean LiDar Sensor is possible: [[LDS25 Auto Clean LiDAT Sensor>>doc:Main.User Manual for LoRaWAN End Nodes.LDS25-LBLDS25-LS--LoRaWAN_LiDAR_Distance_Auto-Clean_Sensor_User_Manual.WebHome]].
64 * Some liquid will emit corrosive gas might destroy the probe when install inside.
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67
68 MicroWave Radar has a advantage is that if the cover of the tank is plastic or wooden, You can place the probe outside of the tank, because MicroWave Radar can get through the cover and get reading.
69
70
71 == 3.2 Advantage & Disadvantage ==
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73
74 (% style="color:blue" %)**Advantage**(%%) :  Able to detect the level. Good Accurancy.
75
76 (% style="color:red" %)**Disadvanage**(%%): Wrong reading when probe is block by moisture or other stuff. Affect by temperature.
77
78
79 = 4. Pressure Sensor =
80
81 == 4.1 How it works? ==
82
83
84 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.
85
86 there are two types , (% style="color:blue" %)**Thread type** (%%)and (% style="color:blue" %)**Immersion type**(%%). as below:
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88
89 [[image:image-20221228143643-1.png||height="223" width="312"]] [[image:image-20221228144206-2.png||height="256" width="335"]]
90
91
92 == 4.2 Advantage & Disadvantage ==
93
94
95 (% style="color:blue" %)**Advantage**(%%) :  Able to detect air / gas / liquid pressure level. Immue to factors such as moisture / blocking. etc. Flexible for installation for
96
97 (% 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.
98
99
100 = 5. Capacitance Sensor (Side Installation) =
101
102 == 5.1 How it works ==
103
104 When there is liquid or none-liquid, the object will shows different capacitance. We can use Capacitance reading to check if the position has liquid or not.
105
106 [[image:1750816596142-762.png||height="323" width="206"]][[image:1750816492900-386.png||height="347" width="433"]]
107
108
109 == 5.2 Advantage & Disadvantage ==
110
111 (% style="color:blue" %)**Advantage**(%%) :  Easy Installation, low power consumption
112
113 (% style="color:red" %)**Disadvanage **(%%): Can only check certain level. not able to give detail reading.
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