Review on VIVOSUN 3-in-1 Digital pH Meter: High Accuracy, ATC, 0-14.0 pH Range by Joseph Long

The only thing this company is good at is making 6 inch vibrating fans. This is the third product I have tried from them; I sterilized, purified and weighed distilled water to ensure the accuracy of the pH solution; Water in the circulation tank to keep it at exactly 77 degrees. The meter calibrates well at 6.86 but then registers 4.00 as 6.72 and 9.18 as 6.97 and keeps calibrating all 3 dilutions at 6.86.2 out of 3 products I bought from them had similar ones Accuracy/consistency issues, the third is a fan and doesn't have it Even so, the motors are questionably weak and spin their oscillating gears under extreme hindrance.