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Version 14.25 by Edwin Chen on 2025/06/25 09:30
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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.
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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.
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Xiaoling 13.2 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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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.
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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 14.25 61 * If the measure range , blind spot and angel fit the tank installation and measuremnt
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Edwin Chen 10.1 63 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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Xiaoling 13.2 66 == 3.2 Advantage & Disadvantage ==
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Xiaoling 13.2 69 (% style="color:blue" %)**Advantage**(%%) :  Able to detect the level. Good Accurancy.
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Xiaoling 13.2 71 (% style="color:red" %)**Disadvanage**(%%): Wrong reading when probe is block by moisture or other stuff. Affect by temperature.
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Xiaoling 13.2 74 = 4. Pressure Sensor =
Edwin Chen 10.1 75
Xiaoling 13.2 76 == 4.1 How it works? ==
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Edwin Chen 13.1 79 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 81 there are two types , (% style="color:blue" %)**Thread type** (%%)and (% style="color:blue" %)**Immersion type**(%%). as below:
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84 [[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 87 == 4.2 Advantage & Disadvantage ==
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Xiaoling 13.2 90 (% 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 91
Edwin Chen 13.7 92 (% 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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Xiaoling 13.2 95
Edwin Chen 5.1 96