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Last modified by Edwin Chen on 2025/06/26 11:53
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Edwin Chen 7.1 1 **~ Table of Contents：**
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3 {{toc/}}
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Edwin Chen 10.1 5
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Xiaoling 13.2 7 = 1. Overview =
Edwin Chen 4.1 8
Xiaoling 13.2 9
Edwin Chen 4.1 10 This URL introduce different methods to detect the water / liquid level.
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Xiaoling 13.2 13 = 2. Flow switch =
Edwin Chen 4.1 14
Xiaoling 13.2 15 == 2.1 How it works ==
Edwin Chen 5.1 16
Xiaoling 13.2 17
Edwin Chen 4.1 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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Xiaoling 13.2 24
Edwin Chen 5.1 25 [[image:image-20221217164432-3.png||height="282" width="501"]][[image:image-20221217164337-2.png||height="279" width="431"]]
Edwin Chen 4.1 26
Edwin Chen 5.1 27 The switch will switch on/off to show if the water / liquid has dedicate level.
Edwin Chen 4.1 28
Edwin Chen 5.1 29
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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Xiaoling 13.2 35 == 2.2 Advantage & Disadvantage ==
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Xiaoling 13.2 38 (% style="color:blue" %)**Advantage**(%%) : Reliable , Easy to install & Immue to different environment.
Edwin Chen 5.1 39
Xiaoling 13.2 40 (% style="color:red" %)**Disadvantage**(%%): Only be able to detect one speicify level. Not able to detect full range of water.
Edwin Chen 5.1 41
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Edwin Chen 14.2 43 = 3. Ultrasonic Sensor / LiDAR Sensor / Microwave Ridar =
Edwin Chen 6.1 44
Xiaoling 13.2 45 == 3.1 How it works? ==
Edwin Chen 10.1 46
Edwin Chen 14.15 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.
Edwin Chen 10.1 48
Edwin Chen 14.15 49
Edwin Chen 14.20 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.
Edwin Chen 14.15 51
Edwin Chen 14.23 52 Below is photo and URL shows how Ultrasonic Sensor works to detect Water Level. LiDAR ToF and MicroWave RiDar are similiar.
Edwin Chen 10.1 53
54 [[https:~~/~~/www.electricalvolt.com/2022/06/ultrasonic-level-transmitter-working/ >>https://www.electricalvolt.com/2022/06/ultrasonic-level-transmitter-working/]]
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56 [[image:image-20221217170756-1.png||height="465" width="539"]]
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Edwin Chen 14.23 59 When choose the these sensors, the consideration are:
Edwin Chen 10.1 60
Edwin Chen 14.27 61 * If the measure range , blind spot and angel fit the tank installation and measurement requirement.
Edwin Chen 14.34 62 * Make sure the liquid on the tank will not touch the top so touch the sensor.
Edwin Chen 18.1 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]].
Edwin Chen 17.1 64 * Some liquid will emit corrosive gas might destroy the probe when install inside.
Edwin Chen 14.23 65
Edwin Chen 10.1 66
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Edwin Chen 14.48 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.
Edwin Chen 14.44 69
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Xiaoling 13.2 71 == 3.2 Advantage & Disadvantage ==
Edwin Chen 10.1 72
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Xiaoling 13.2 74 (% style="color:blue" %)**Advantage**(%%) :  Able to detect the level. Good Accurancy.
Edwin Chen 10.1 75
Xiaoling 13.2 76 (% style="color:red" %)**Disadvanage**(%%): Wrong reading when probe is block by moisture or other stuff. Affect by temperature.
Edwin Chen 10.1 77
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Xiaoling 13.2 79 = 4. Pressure Sensor =
Edwin Chen 10.1 80
Xiaoling 13.2 81 == 4.1 How it works? ==
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Edwin Chen 13.1 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.
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Xiaoling 13.2 86 there are two types , (% style="color:blue" %)**Thread type** (%%)and (% style="color:blue" %)**Immersion type**(%%). as below:
Edwin Chen 13.1 87
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89 [[image:image-20221228143643-1.png||height="223" width="312"]] [[image:image-20221228144206-2.png||height="256" width="335"]]
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Xiaoling 13.2 92 == 4.2 Advantage & Disadvantage ==
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Xiaoling 13.2 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
Edwin Chen 13.1 96
Edwin Chen 13.7 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.
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Edwin Chen 14.50 100 = 5. Capacitance Sensor (Side Installation) =
Xiaoling 13.2 101
Edwin Chen 14.50 102 == 5.1 How it works ==
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Edwin Chen 15.2 104 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.
Edwin Chen 14.50 105
Edwin Chen 16.2 106 [[image:1750816596142-762.png||height="323" width="206"]][[image:1750816492900-386.png||height="347" width="433"]]
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Edwin Chen 16.2 109 == 5.2 Advantage & Disadvantage ==
Edwin Chen 15.2 110
Edwin Chen 16.2 111 (% style="color:blue" %)**Advantage**(%%) :  Easy Installation, low power consumption
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Edwin Chen 16.5 113 (% style="color:red" %)**Disadvanage **(%%): Can only check certain level. not able to give detail reading.
Edwin Chen 16.2 114
Edwin Chen 5.1 115