PH & Temp Meter pH-991


PH Meter Tester Water Quality Online monitor PH & Temp Meter pH-991 Acidimeter Analyzer for Aquarium Swimming pool


Automatic shutdown

Backlight Display

Online monitoring

Range: pH 0.00 ~ 14.00

TEMP: -50°C ~ 70°C (-58°F ~ 158°F)

Resolution: pH 0.01

TEMP: 0.1°C (0.2°F)

Accuracy: pH ± 0.1

TEMP: ±1.0°C (±2.0°F)

Temperature Compensation: 0°C  ~ 50°C (32°F ~ 122°F)

Environmental temperature: 0°C ~ 50°C (32°F~ 122°C)

Power supply:  DC  6V (Power Adapter Usable)

Battery: 4×1.5V AG-13 Button Cell Batteries (NOT Included)


Remove the protective cap, put the ph electrode BNC connector into electrode socket .

Press the "ON/OFF" to switch power .

Remove the protective cap ,clean the PH electrode with distilled water ,and dry by filter paper .Dip into the testing liquid ,and shake it for a while .Then wait until the value become stable .The final value will be the ph result .

After use ,switch off it ,Use the distilled water clean the electro de and replace the protective cap .(Note: The screen shows PH(first line ),Temperature .


1.Immerse the electrode in ph 6.86(under the temperature of 25°C)standard the buffer solution of phosphate ,and gently shake the electrode .

2.Rugulate the trimmer with a screwdriver until the buffer solution value corresponding to the measurement temperature is obtained .

3.Immerse the electrode in ph 4.01 or PH 9.18 the standard buffer solution of borax.

4.After about  one minute ,until the buffer solution value corresponding to the measurement temperature is obtained.


The instrument's ph range must be recalibrated whenever :

The electrode has been used (laid )for long time from the last calibration.

The electrode has been used in particularly taxing conditions .

The utmost accuracy is required .


if the screen darkens or gets fuzzy or the error is large ,batteries should be  replaced. just pull out the battery case and release it .pay attention to the directions. Please connect the power adaptor for long -time testing .

Kit include:

1 x PH & Temp Meter pH-991

41 JD
46 JD
In stock

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