TDS Meter Probe Water Quality Monitoring V1 Sensor Module with XH2.54-3Pin Jumper Wire Connector for Arduino

I bought this and the turbidity sensor to add to my K40 laser cutter setup. This thing turned out perfect. My issue is that it is cooled by water in a bucket in a place I can't see, so it makes it hard to tell if there's algae etc in the water. This sensor gives me instant readings. I just used the example code from the wiki and I was off to the races.

Leaving 5 stars for now, because it seems to be working, even if it isn't hugely accurate out-of-the-box. Plan on compensating and calibrating (still trying to figure out calibration). I'm using an ESP32 to handle this project, which is long-term "permanent" monitoring of TDS in my freshwater aquarium. Ignore the other review that complained about how much memory is required for compensation code, unless you are using an arduino, I guess. With the existence of ESP32, and the fact that you can program these identically to arduinos in the Arduino IDE, I don't know why you would buy an arduino instead of an ESP32, tbh. Other reviews state that the sensor only goes up to 1000ppm. This is observably false, mine went up to 2500ppm, at least (also unrelated... I need to change my aquarium water!). I didn't seem to hit a ceiling, although obviously there is one. It is possible that the other folks were using 3.3vdc instead of 5vdc, but newer ESP32 boards like mine (and pretty much any that have USB-C input/power) have both 5vdc from USB, and 3.3 via an onboard voltage regulator. I believe it is likely that using 5v is increasing the resolution and max observable PPM. My one concern with long-term use is electrolysis of the probe. It appears to be stainless steel, but I can clearly see the effects of electrolysis etching on the prongs. This could also be a design error in my code: I'm currently running 30 rapid tests and averaging them every second. After I complete the prototyping phase and actually solder everything to a board, I might turn the refresh down on that significantly, so it only runs a test once a second and averages over a longer period of time. Not sure yet how I want to approach that. Regardless, if I begin to see significant electrolysis etching, I will likely reduce this from 5 stars to 3 or even lower, as this would indicate a low-quality steel was used for the prongs.

I bought two of these to measure the TDS of the water going into my reverse osmosis system and the levels coming out. This way I know when to change the filters without just blindly doing so every x number of months. The data is logged into Home Assistant and I get a push notification when I need to replace them now. I originally connected these sensors to the analog-to-digital (ADC) on an ESP32 microcontroller, testing it in both the Arduino IDE and ESPHome. The voltage was all over the place and produced garage readings. I ended up using instead an ADS1115 (16-Bit, 4 channel ADC) and connected it to the ESP32 via the I2C interface. This eliminated most of the problems of repeatability and I was finally getting consistent readings. HOWEVER, there was still a lot of variation in readings from one probe to the next. I had to individually calibrate each sensor to correct this. There's sample Arduino for this product online which contains a calibration formula--ignore it, it's completely useless. Instead, I made eight different concentrations of a calibration solution by mixing lab-grade deionized water and table salt. I then plotted the observed voltage at each concentration and came up a linear calibration curve using the least squares means method. (This sounds complex but is rather easy to setup using the "calibrate_linear" filter in ESPHome). I did this for each of the two senors, making a unique calibration profile for each. Everything now works and is reasonably accurate for my needs. I am somewhat concerned about long-term drift but will update this review with my experiences over time.

good

heck it works, but if you want accuracy with your projects the nature of a 0-2.6v analog value is a bit silly when measuring TDS via water conductivity, especially when compensation code fills more than 50% of your program area, would have been better if it was an SPI or similar serial stream that can be queried at a whim to get a fixed number of 0-1023(10 bit number that fits the 0-9999 TDS measurement range) they are cool and the amber power light isn't stupid like some green and blue LED's being run at the same current as red ones so you literally have to snap it off to not be blinded when you leave a setup running at night

No es el mejor sensor para medir PPM, pero por el precio te saca de un apuro.

El pcb pudiera ser mas pequeño

works for 3 weeks+ - later you need a new one

KEYESTUDIOのサイトにあるプログラムを見て、Raspbery PI PicoのMicropythonに書き換えてみた。 とりあえず、値は示しているようだ。 水道水を測定すると60ppmくらいで、伊右衛門を測定すると220ppmくらいを示している。 正しいのかどうかは分からんが、一応日本の水道水は100ppm目標らしいので合ってるのかも？ 一応、DS18B20も購入し温度補正は行っている。（こちらは棒温度計と比較し正確性は検証済み） 校正液買わなきゃなと思いつつふと思い出した、10年くらい前にアピストやってた頃にマーフィードのTDSメータ（すでに壊れて比較には使えん）買った際に校正液も買ったことに。 冷蔵庫の野菜庫に隠したのを掘り出して計測してみた。 これは、瓶には、650ppmと書いて有るが、実際計測すると350ppm程度にしかならない。 これは可能性として以下の事が考えられる。 ・式間違っとる ・校正液が古すぎてまともな値を示していない ・センサが壊れている。 つう訳で今度ショップでまっとうな校正液買って来てから追試験することにしよう。 Amazonで探してみたが、マーフィードのはAmazon発送のがないので送料の方が高い（流石に6~700円の代物に/～800円の送料払う気にならんわ。）か、無駄に高い校正液しかないので。^^;

bonne petite sonde arduino

Funziona bene, ho fatto un progetto con Raspberry Pico e Micropython e funziona.

Es tan poco preciso que no sirve.

Misura la conducibilita di un liquido, in genere si usa per l'acqua, per avere una idea della quantita di sali in essa disciolti, nello specifico lo uso per gli acquari. Al momento pare che la misurazione sia abbastanza ripetitiva. L'unica nota negativa e' la lunghezza del cavo della sonda di circa 50 cm, che avrei preferito piu lunga anche perche la sonda non e' facilmente autocostruibile, mi tocchera' allungarne il cavo ad entrambe, ma certo, accorciare e' un lavoro che sicuramente esce piu' pulito e meno problematico per affidabilita nel tempo di allungare, per questo 4 stelle.