Quick start guide – Hach-Lange SI792 P series Quick Start Guide User Manual

Page 2

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© Hach Company, 2007. All rights reserved. Printed in Germany.

For technical assistance or ordering information: visit

www.hach.com

, call 800-227-4224 or email [email protected] Edition 1 December 2007

Quick Start Guide

For si792 P series 2-wire transmitters

DOC016.53.00794

7. Calibrate the sensor. The two most common calibration methods are described below. Refer to
the user manual for other details. Refer to

Table 4

for default passcode settings.

Calibration with automatic buffer recognition
Complete the following steps to calibrate the pH probe:
a. Press

CAL

, enter passcode: 1100,

ENTER

. The display will show CAL1.

b Remove the pH and temperature probes from the process. Clean the probes and immerse

in the first buffer solution (any order). Briefly stir the solution with the probes.

c Press

ENTER

. Automatic recognition of the buffer solution will begin. The display will first

show the hourglass and no buffer value, then the recognized buffer value followed by the
measured millivolt value. When the measurement is complete, the display will show CAL2.

d When CAL2 is displayed, remove the probes from the first buffer solution and rinse thor-

oughly.

e Complete a one-point calibration or start a two-point calibration:

One-point calibration: press CAL to end the calibration. The slope (%) and offset (mV) of the

probe (based on 25 °C) will be displayed.

Two-point calibration: immerse the probes in the second buffer solution. Press ENTER. The

buffer detection will repeat as for the first buffer solution. When complete, the slope (%) and off-
set (mV) of the probe (based on 25 °C) will be displayed.

f Press

ENTER

,

ENTER

to return to the measurement mode. The HOLD mode will remain

active for 20 seconds.

g Remove the probes from the buffer, rinse and return to the process.

Calibration by Comparison
The probe can be calibrated by entering the sample value from measurement in an instru-
ment such as a laboratory or portable meter (one-point calibration). The probe does not need
to be removed from the process during calibration. The sample temperature should corre-
spond to the measured process temperature for accurate results.
a. Press

CAL

, enter passcode:

1105

,

ENTER

. The display will briefly show CAL PRD and

then StorE.

b Collect a grab sample for measurement in the lab. Press

ENTER

to store the sample value

in the transmitter.

c The cal mode indicator will flash to indicate that calibration is not complete. The transmit-

ter will continue to measure and display the current sample values.

d Measure the grab sample with a laboratory or portable meter.
e Press

CAL

, enter passcode:

1105

,

ENTER

to access the product calibration once more.

The display will briefly show CAL PRD and then CALC.

f Edit the displayed value to match the value measured by the laboratory or portable meter

and press

ENTER

. The slope and offset will be shown.

g Press

ENTER

to end the calibration. The display will show the measured value alternating

with Hold.

h Press

ENTER

to return to the measuring mode. The outputs will remain in the hold mode

for approximately 20 seconds.

Note:For comparison calibration via Foundation Fieldbus, see the pH user manual,

DOC026.53.00794. Comparison calibration via Profibus is not available.

Table 4 Default passcode settings

Display

Function

Default setting

Cal INFO

Calibration information

0000

CAL 0-CAL

Calibration zero

1001 (not for
si792x P-PA)

CAL CAL

Calibration

1100

CAL PROD

Product calibration

1105 (not for
si792x P-PA)

CAL RTD

Temperature probe adjustment

1015

CFG ERR

Error information

0000

CFG CONF

Configuration

1200

CFG SNSR MO Sensor monitor

2222

CFG OUT

Current source

5555

CFG SPCL ST

Administrator passcode. Use

ARROW

keys to

select NO or YES

1989

NO SPCL ST

Do not change
administrator passcode

Press

ENTER

to return to the default

passcode
Press

CONF

to exit the editor

YES SPCL ST

Change administrator
passcode

Press

ENTER

to accept the new

passcode
Press

CONF

to exit the editor

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