This is a laboratory probe, it can't be immersed in the liquid for too long time. You can check here for the whole Analog pH Sensor / Meter Pro Kit For Arduino or a spare Industrial Probe as a replacement

What is pH?  

“pH stands for the power of hydrogen, which is a measurement of the hydrogen ion concentration in the body. The total pH scale ranges from 1 to 14, with 7 considered to be neutral. A pH less than 7 is said to be acidic and solutions with a pH greater than 7 are basic or alkaline.” 

Arduino et mesure de pH avec sonde DFROBOT SEN0161 (pH-mètre)

Note: Buffer solutions are not included.
After you received your package! You may found some white particles on the protection foam which is the KCl crystallization from the cap. Please don't worry about the crystallization in the packing box, that's normal. Actually, since the transportation restriction on liquid, we have poured out the KCL3N solution in the cap, the slight crystallization in the packing box should be leaked since the remnant. Anyway, once you received the probe, you should store it in KCL3N solution, you can not leave it in dry circumstances.

• Water quality testing
• Aquaculture

Gravity: Analog pH Sensor / Meter Kit For Arduino TECH SPECS

• Module Power: 5.00V
• Module Size : 43 x 32mm(1.69x1.26")
• Measuring Range :0 - 14PH
• Measuring Temperature: 0 - 60 ℃
• Accuracy : ± 0.1pH (25 ℃)
• Response Time: ≤ 1min
• pH Sensor with BNC Connector
• pH2.0 Interface (3-foot patch )
• Gain Adjustment Potentiometer
• Power Indicator LED

Microbit Project 2: Drinking Cola equals Drinking Toilet Cleaner?

Required components of the project include:

Micro:bit×1

RGB lamp ring expansion board ×1

PH sensor ×1

• Wiki (PH meter)
• pH and EC Probe Holder 3D Model (by Rayuela)
  
• Schematic
• PCB layout
• PH composite electrode manual
• Arduino sample code / ph sensor arduino
• Zips for all above

• Gravity: Analog pH Sensor / Meter Kit For Arduino x1
• pH probe (BNC connector)  x1
• pH sensor circuit board       x1
• Analog cable                      x1