Myron L Ultrameter 6P, Operation Manual

Page: 9 / 26

a. While in “USER” mode, press .
b. Press twice (to skip over tempco adjustment), and
“ RATIO ” will appear (see Figure 4).
c. Adjust with or
keys until new conversion
ratio is displayed.
d. Press twice (to skip
over calibration adjustment)
to accept new conversion ratio.
You are now ready to measure samples with the new
conductivity/TDS ratio.
VI. CALIBRATION
A. Calibration Intervals
Generally, calibration is recommended about once per month with
Conductivity or TDS solutions. Calibration with pH solutions should be
checked twice a month. Calibration of ORP is not necessary (ref.
Calibration Intervals, pg. 23).
B. Rules for Calibration in the Ultrameter
1. Calibration Steps
a. Starting Calibration
Calibration is begun by pressing while measuring Conductivity,
TDS or pH. Measuring continues, but the CAL icon is on, indicating
calibration is now changeable.
The reading is changed with the and to match the known
value. The calibration for each of the 4 solution types may be performed
from either conductivity or TDS mode.
14
CAL
MCLR
M S
MR
In these first five sections, you have learned
all you need to make accurate measurements.
The following sections contain calibration,
advanced operations and technical information.
M S
MR
CAL
MCLR
CAL
MCLR
T D S
Figure 4
TDS
RATIO
User
Depending on what is being calibrated, there may be 1, 2 or 3 steps to
the calibration procedures.
The becomes an “ACCEPT” key. At each point, pressing
accepts the new calibration value and steps you to the next adjustment
(or out of CAL mode if there are no more steps).
To bypass a calibration step, just press to accept the present value
as is.
c. Leaving Calibration
You know you are finished when the “ CAL ” icon goes out. Pressing any
measurement key abandons changes not yet accepted and exits
calibration mode.
Leaving pH after the 2nd buffer results in the same gain being entered in
place of the 3rd buffer.
2. Calibration Limits
There are calibration limits. A nominal “FAC” value is an ideal value stored
by the factory. Attempts to calibrate too far, up or down, from there will
cause the displayed value to be replaced with “FAC”. If you accept it
(press the “Cal” key), you will have the original default factory calibration
for this measurement. The need to calibrate so far out that “FAC” appears
indicates a procedural problem, wrong standard solution, a very dirty cell
cup or a dying pH/ORP sensor (ref. Troubleshooting Chart, pg. 27).
C. Calibration Procedures
1. Conductivity or TDS Calibration
a. Rinse conductivity cell three times with proper standard (KCl,
NaCl, or 442) (ref. Cond./TDS Standard Solutions, pg. 28). For
user calibration see User Calibration Conductivity/TDS, pg. 16.
15
KCl, NaCl or 442 User
Cond Gain only Tempco, then Gain
Res Done in conductivity Done in conductivity or TDS
TDS Gain only Tempco, Ratio, then Gain
pH 7, acid and/or base
ORP Zero set with pH 7 automatically
CAL
MCLR
CAL
MCLR
CAL
MCLR