jenway 370 Operating Manual

370 350/REV A/10-03

MODEL 370 pH/mV METER

OPERATING MANUAL

MODEL 370

pH/mV METER

OPERATING INSTRUCTIONS

CONTENTS

Introduction 1
Specification 1
Installation 2
Displays 2-3
Controls 4
Operation 5
Calibration 5-7
Error Codes 8
mV Mode 8-9
Manual Temperature Compensation 9
Auto Shut Off 9
Data Storage 10
Good Practice Guidelines 11
Maintenance 12
Troubleshooting Guide 13-14
Checking pH Electrode Function 14
Checking pH Meter Function 15
Checking Temperature Input 15
Battery Replacement 16
Optional Accessories 16
Spare Parts 16
EC Declaration of Conformity 17

MODEL 370

pH/mV METER

OPERATING INSTRUCTIONS

INTRODUCTION

The Model 370 is a general purpose hand held pH/mV meter
offering a 1 or 2 point calibration and automatic buffer recognition
with manual override. The custom liquid crystal display
simultaneously shows temperature compensated pH readings or
electrode potential and temperature. The instrument is housed in a
robust, ergonomically designed case. Calibration errors are clearly
indicated together with the parameter in error. An indication of
battery life is also permanently shown on the display. An
automatic switch off facility helps to conserve battery life.

SPECIFICATION

pH (1 or 2 point cal)
Range: -2 to 16.00pH
Resolution/Accuracy: 0.01pH / ±0.02pH
mV (Absolute or Relative)
Range: -1999 to +1999mV
Resolution/Accuracy: 1mV / ±1mV
Temperature Ranges: -10 to +105°C / 14 to 221°F
Resolution/Accuracy: 0.1°C / ±0.5°C / 1°F / ±1°F
ATC Range: 0 to 100°C / 32 to 212°F
Manual Temp. Comp. Range: 0 to 100°C / 32 to 212°F
Auto Buffer Recognition: 4.00, 7.00, 9.22, 10.00

(manual override)
Calibration: User selectable 1or 2 pt
Power: 2 AA cells
Battery Life: 500 hours typical

(@ 25°C with alkaline cells)
Size: 175(l)x75(w)x35(d)mm
Weight: 250g

1

INSTALLATION

Unpack the instrument and ensure the following items are present:

1. Model 370 pH/mV Meter (370 201)

2. Epoxy bodied combination pH electrode (924 001)

3. Temperature/ATC probe (027 500)

4. pH4, 7 & 10 buffer sachets

5. 2 x AA alkaline batteries (021 007)(fitted)

Optional accessories which may have been ordered:

1. Carrying Case (033 268)

1. Main display - 3½ digit display providing direct readout of

pH or mV. Underrange (-1) and Overrange (1) symbols will
be displayed if the instrument is reading outside the
ranges of:
pH -2.00 to 16.00 or mV -1999 to +1999
In addition, the instrument will display an erroneous
result momentarily at the same time as the secondary
display indicates the error code.

DISPLAYS

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2. Secondary display - 4 digit display showing
temperature (manual temperature compensation value or
ATC probe temperature, if connected) in °C or °F. In the
event of a calibration error the display will show an
error code momentarily (if the reading is outside the
range of -10 to 105°C / 14 to 220°F) at the same time as
the primary display indicates the erroneous reading.
These codes will be shown as Err1, Err2 or Err3.

3. CAL 1 or CAL 2 indicator - shows which point of the
calibration routine has been reached.

4. Battery Life Indication - 4 levels will be shown ranging
from <25%, 25-50%, 50-75% and 75-100%. Sensor
calibration data and user parameters are retained during
battery replacement.

5. Mode annunciator - pH or mV is displayed depending on
which mode of operation is selected.

6. REL - this is the relative mV mode annunciator. The
relative mV mode is selected via the Cal key. If the mV
mode is selected and this annunciator is not shown then
the instrument is reading in absolute mV.

7. MAN - this is displayed to indicate when manual
temperature compensation or manual pH calibration is
being performed. This will not appear on the display
when the ATC probe is connected.

8. RCL annunciator - this indicates that the displayed
reading is the stored value recalled from memory.

KEYPAD CONTROLS

STO RCL STO stores the current data reading.

RCL enters recall mode to view the stored
readings.

I:O Switches the instrument on and off. This key

should be pressed and held for 1-2 seconds to
operate. The instrument will automatically switch
off after 30 minutes if no key is pressed.

Back light. Pressing this key will illuminate the
back light for 10 seconds. It should be noted
that, if used excessively, this will reduce battery
life.

Enables manual setting of pH buffer values when
performing a calibration, and adjustment of the
manual temperature compensation value (no ATC
probe connected).

CAL This key is used to select and perform

calibration in the pH mode. In the mV mode
pressing the Cal key will toggle between Absolute
and Relative mV.

MODE This key changes the measurement parameter

to pH or mV mode as required and sets to °C/°F.
Press and hold for 3 seconds to select temperature
unit.

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4

OPERATION

Switch the instrument on by holding down the I/O key for 1-2
seconds. All display segments will be illuminated for approximately
2 seconds. The display will either power up in the mV or pH mode
depending upon previous usage. An internal self check routine is
run during this display and on successful completion normal
operating mode is activated.

If no ATC probe is connected to the instrument the MAN
annunciator will be shown. Manual temperature compensation
should always be entered prior to commencing a calibration.

Remove the electrode from the packaging and ensure it is in good
condition. Connect the electrode to the instrument via the BNC
socket and remove the wetting cap. Prior to performing pH
measurement it is necessary to perform a 1 or 2 point calibration
using the buffer sachet(s) provided. Connect the ATC probe (if
being used) to the mini-DIN socket and immerse the ATC probe in
the pH buffer alongside the pH probe.

CALIBRATION

The 370 features a one or two point calibration. For the best
results we recommend that the 370 is calibrated with buffer
solutions that are close to the sample value, where possible. For
example: when working at pH5.5 we recommend calibrating at
pH7 and pH4.

Auto buffer recognition operates over the range of 0 to 100°C,
and will recognise 4.00, 7.00, 9.22 and 10.00pH. Alternative
manual values may be entered during the calibration sequence by
using the keys to set the preferred values.

NOTE: Manual temperature compensation (if being used) should
be entered prior to commencing a calibration sequence using the
keys. (If the displayed reading is altered the auto buffer

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