Sper Scientific 860031 pH - mV Bench-Top Meter - Manual (Page 53)

53
MAINTENANCE
 Do NOT touch the surface of the conductivity probe’s
testing element with hard objects.
 Do NOT use anything to rub the platinum black surface
of the probe or the original constants will be changed
and the testing range will be affected.
 If the surface of the testing element becomes
contaminated, place the probe into diluted detergent or
diluted acid for about 15 minutes, then rinse the probe
with distilled water.
ORP Probe
Before using, remove the soaking bottle, soak the probe in
distilled water, and rinse. Gently dry the sensing el-
ement.
Probe Testing
1. Connect the ORP probe to the meter via the BNC
connector.
2. Put the probe in a buffer solution of pH 7.00 with sat-
urated quinhydrone.
3. Stir; mV reading (E1) should be 86 ±15 mV.
4. Rinse the probe with distilled water, then set the probe
in pH 4.01 buffer solution with saturated quinhydrone.
After stabilizing, record the mV meter reading (E2). The
difference between E1 and E2 should be 165 mV.
5. Rinse the probe with distilled water between each use.
Keep the ORP probe wet. If not in use for long periods,