Table 2.

pH estimation results for a few other BS and PBS samples. pH 6.0 BS (Ricca), pH 6.5 BS (EMS), and pH 7.4 PBS (Gibco) are used.

Smartphone	pH (Ideal)	Estimated pH (with Four Captures)				Avg. |Err.|	Std. Dev.
		1	2	3	4
A	6.0 BS	6.1	6.1	6.1	6.1	0.10	0.00
	6.5 BS	6.6	6.6	6.6	6.6	0.10	0.00
	7.4 PBS	8.4	8.4	8.4	8.4	1.00	0.00
B	6.0 BS	6.0	6.1	6.1	6.1	0.07	0.04
	6.5 BS	6.5	6.5	6.4	6.3	0.08	0.08
	7.4 PBS	8.2	8.3	8.2	8.3	0.85	0.05
C	6.0 BS	6.2	6.1	6.1	6.1	0.13	0.04
	6.5 BS	6.7	6.6	6.7	6.7	0.18	0.04
	7.4 PBS	8.5	8.4	8.5	8.5	1.08	0.04