TESTO 205 Documentation

7. Questions and Answers
12
7. Questions and Answers
Question Possible causes Possible solution
Readings instable. Static charge. Rinse off pH electrode
with tap water or
low concentration
soap water.
Air cushion from measurement Shake pH electrode in a
electrode gets into measurement downward direction like
tip. with a fever thermometer.
pH electrode has dried out. Place pH electrode for
several hours in water or
diluted hydrochloric acid.
lights up. Remaining capacity of battery Change battery (See
< 10h. 6.4 Changing battery,
P. 11)
Instrument switches Auto Off function is switched on. Auto Off.
itself off. (See 5.2 Setting
instrument, P. 8)
Er1 lights up. Invalid gradient value Recalibrate instrument,
of pH electrode. a new buffer solution
could be used.
pH electrode defective. Change probe.
Er2 lights up. Invalid offset value Recalibrate instrument,
of the pH electrode. a new buffer solution
could be used.
pH electrode defective. Change probe.
Er3 lights up. Invalid gradient value Recalibrate instrument,
of pH electrode following a new buffer solution
3 point calibration. could be used.
pH electrode defective. Change probe.
Er4 lights up. Probe not inserted correctly. Check connection.
pH electrode defective. Change probe.

TESTO 205 Specifications

General

Product type	pH meter
Measuring range (pH)	0 to 14 pH
Accuracy (pH)	±0.02 pH
Resolution (pH)	0.01 pH
Operating temperature	0 to +50 °C
Storage temperature	-20 to +70 °C
Protection class	IP65
Weight	135 g
Temperature measuring range	0 to +60 °C
Temperature resolution	0.1 °C
Temperature accuracy	±0.5 °C
Battery type	4 x LR44
Battery life	Approx. 80 h