Comparison to Other pH Devices Comparison to Other pH Devices

gopher Comparison to Other pH Devices

SPECIFICATION	GOPHER	GLASS ELECTRODE	FLUORESCENT	BLOOD GAS ANALYZER
Non-Invasive	Yes	No	Yes	No
Measurses pH	Yes	Yes	Interprets pH	Interprets pH
Calibration Required	Yes	Yes	Yes¹	Yes
Labor Time	5-10 min	10-15 min	10-20 min	5-10 min
Storage	Dry or Wet	Wet	Dispose	Dispose
Reuseable	Yes	Yes	No	No
Drift	Low	Low	High	N/A
Cables/Wires	No	Yes	Yes	No
Response Time	10 usec	1 sec	30 sec	N/A
Temperature	Compensated	Compensated	N/A	N/A
Alert Notifications	Yes	No	Yes	No
pH Trending	Yes	No	Yes	No
Accuracy (Instrument)	0.02 pH	0.02 pH	0.05 pH	0.03 pH²
Accuracy (Method)³	0.03 pH	0.10 – 0.19 pH	0.15 – 0.26 pH	0.08 – 0.16 pH

¹Calibration requires alignment tool and calibration of a pH glass electrode probe

² Accuracy is not stated in literature but an estimate is provided in this table

Total Method Uncertainties

gopher

Error	Lo	Hi
Buffer A	0.002	0.002
Buffer B	0.005	0.005
Instrument	0.02	0.02
Sampling	0.00	0.00
TOTAL ERROR (pH Units)	0.03	0.03

Glass Electrode

Error	Lo	Hi
Buffer 1	0.01	0.02
Buffer 2	0.01	0.02
Buffer 3	0.01	0.02
Instrument	0.02	0.03
Sampling	0.05	0.10
TOTAL ERROR (pH Units)	0.10	0.19

Sampling error is based on assumptions without any scientific data.

Fluorescent

Error	Lo	Hi
Buffer 1 (pH Meter)	0.01	0.02
Buffer 2 (pH Meter)	0.01	0.02
Buffer 3, if applicable (pH Meter)	0.00	0.02
pH Meter	0.02	0.03
Calibration Factor	0.08	0.12
Instrument	0.03	0.05
Sampling	0.00	0.00
TOTAL ERROR (pH Units)	0.15	0.26

The calibration factor is derived from the standard calibration rule that when using another tool such as a pH meter to calibrate the fluorescence instrument, the error from the pH meter must be multiplied by a minimum factor of 4 and added to the total error.

Blood Gas Analyzer

Error	Lo	Hi
Calibration Standard	0.01	0.03
Instrument	0.02	0.04
Sampling	0.05	0.10
TOTAL ERROR (pH Units)	0.08	0.17

Sampling error is based on assumptions without any scientific data.