ARCHIVED REPORTS_XR0006259 - Laserfiche WebLink

Home Browse Search

Section No 8 • Revision No 0 Date September 5, 1991 Page 3 of 5 8 1 4 2 Calibration - Calibration of the Dissolved Oxygen Meter is performed as described in the instruction manual, a copy of which shall be kept with the instrument at all times Salient features of the recommended calibration procedure (i e , air calibration) are listed below During calibration, it is important that the instrument be placed in the intended operating position Following preparation of the probe (see Manual) , calibration proceeds as follows - r With switch in- the OFF position, adjust the meter pointer to Zero with the screw in the center of the meter panel Readjustment may be necessary if the instrument position is changed - _ ■ Switch to ZERO and adjust to zero with zero control knob ■ Switch to FULL SCALE and adjust the FULL SCALE knob until the meter needle aligns with the "15" mark on the mg/l scale �R Attachthe-preparedprobe to the PROBE connector of the instrument - -- - and,adjust=the_retai.ning=ring_fxnger tight - - ■ Before calibrating allow 15 minutes for optimum probe stabilization Repolarize whenever the instrument has been OFF or the probe has been disconnected ■ Switch to CALIB 02 position ■ Place the probe in moist air Probes can be placed in YSI 5075A Calibration Chamber or the small calibration bottle (the one with the hole in the bottom) along with a few drops of water The probe can also be wrapped loosely in a damp cloth taking care the cloth does not touch the membrane Wait approximately 10 minutes for temperature stabilization This may be done simultaneously while the probe is stabilizing ■ With the CALIB Knob set the meter pointer to the mark for the local altitude Be sure reading is steady For calibration at altitudes higher than 7000 feet above sea level, see Table II of manual Recalibration is recommended when altitude is changed A 1000 ft altitude change can result in a 3 percent reading error - 0 3 mg/l at 10 0 mg/l i1 8-3