The buffer in acidic range is a mixture of a weak acid and salt of conjugate base of the weak acid. And a buffer in a basic region is a mixture of weak base and salt of conjugate acid of weak base. Buffers are substances that minimize changes in concentrations of ions i.e. either H+ ions or OH- ions.
eBay
Unique Display Settings: Choose from PPM, PPT, or % to suit your testing needs with ranges such as Swimming Pool Salt : 0-9999ppm; Seawater : 10-200ppt; Food : 0.01-25%. Wide Application: Perfect for monitoring salt levels in pools, aquariums, Koi fish habitats, and seawater systems.
eBay
Suitable for any aquarium industry, fishing industry, swimming pool, spa, school laboratory, food and beverage,drinking water,etc. The yellow one : test water PH. Accuracy: 0.1ph. If it is not used often, it can be corrected once in March-June!
eBay
1 tester+1 instruction+3 bags of pH test powder. Ph value test pen; OEM customization. Ph test pen. Display mode; Digital display. Accuracy; zero point zero one. Probe type; Glass probe. Temperature compensation range; 0-50（℃）.
eBay
The Bluelab Combo Meter is a versatile all-in-one tool for measuring pH, EC, PPM, and temperature in hydroponics systems. This portable meter from Bluelab features thermal measuring technology and is made of durable plastic material. With the ability to display measurements in both Celsius and Fahrenheit, this meter is designed for easy use in various hydroponic setups. The Bluelab METCOM model offers combined readings for pH, EC, and temperature, making it a convenient and practical choice for maintaining optimal growing conditions.
eBay
Can be used for: water purifiers and filters, food (vegetables, fruits) and beverage quality monitoring, swimming pools and spas, aquariums, hydroponics. TDS&EC Tester. Type: PH Tester. Accuracy: ±0.2PH; ±0.1PH (20°C).
eBay
Press shift to switch between different modes. 1 TDS EC (Battery Included.). 3.5 minutes automatic shutdown. Save power and extend battery life. Temperature range: 0.1-80.0℃(32.0-176.0℉).
eBay
AQUA MASTER COMBO PEN P100. The updated Combo Pen P100 Pro features a modern and robust housing. Press the MODE button to switch between PH and EC. Wait a few seconds for the correct value to appear on the display.
eBay