ECD L20 User Manual

Model L20

Instruction Manual

Microprocessor based

pH, ORP, Temperature

Bench Top Meter

Electro-Chemical Devices, Inc.

1681 Kettering, Irvine, CA 92614 USA

Telephone: [phone]

FAX: [phone]

www.ecdi.com

Contents

General Introduction………………………. 3

Initial Inspection……………………………... 3

Powering the Unit……………………………. 4

Installing the Batteries…………………….. 4

Display and Key Functions……………….. 5

Operational Procedures………………….. 7

Buffer Set Selection………………………… 7

• pH Calibration………………………………. 7

• pH Measurements………………………… 11

• Temperature Measurements……….. 13

• mV Measurements………………………. 13

pH Buffer Tables……………………………. 14

Error Displays & Troubleshooting….. 15

Specifications………………………………… 16

Warranty………………………………………. 18

2

General Introduction

Thank you for selecting the Model L20 pH meter. The Model L20 is
a precision tool that measures pH, mV, ORP and temperature. A
built-in microprocessor stores, calculates and compensates for all
parameters related to pH determinations including pH electrode
temperature characteristics, electrode slope deviations and buffer
solutions.
This meter has a waterproof IP54 case. The mechanical keys are
highly reliable with tactile and audio feedback. This meter is
powered by six AAA size alkaline batteries or with a UL approved
AC adapter (Output 9VDC). The meter also displays a “BAT”
message when the batteries are in need of replacement. Re­calibration is not required when power is restored.
The front of the meter has a large LCD that displays pH or mV and
temperature simultaneously along with user prompts and mode
indicators. The unit prompts the user through calibration and
measurement procedures.
An AUTOLOCK feature for both pH and mV measurements
enables the unit to automatically sense the end point and “HOLD”
the display to indicate the end point value of a measurement.
AUTOLOCK and user prompts help eliminate most errors in
determining pH and mV values, resulting in precise, repeatable
and error-free measurements. The Model L20 can also be used in
non-AUTOLOCK mode.
The Model L20 is available with pH, ORP and ATC (Automatic
Temperature Compensation) probes. Other features include
single, dual or three point calibration, electrode offset
recognition, electrode slope recognition; electrode efficiency
display, built-in buffer coefficients, automatic or manual
temperature compensation, long battery life, and 50/60Hz AC
noise rejection. This meter is user-friendly, for field, industrial and
laboratory applications.

Initial Inspection

Carefully unpack the unit and accessories. Inspect for damages
made in shipment. If any damage is found, notify your ECD
representative immediately. All packing materials should be saved
until satisfactory operation is confirmed.

3

Powering the Unit

The model pH6175 can be powered by an 115V or 230VAC adaptor
as well as 6 “AAA” alkaline batteries. Check the label on the AC 3
adaptor supplied with the instrument to make sure that the AC line
voltage is correct. If the wrong AC adaptor is supplied, notify your
ECD representative immediately.

Installing the Batteries

The Model L20 pH met er is packaged with 6 “AAA” alkaline
batteries required for operation. To insert the batteries into the
meter, follow the procedure outlined below.

1. Use two hands to fl ip the buckles and battery cover to
expose the battery compartment. (Figure 1)

2. Note the polarity and insert the batteries into the battery
compartment correctly.

3. Replace the battery cover.

Figure 1

4

Display and Key Functions

1. WAIT

reading or end point sensing.

7. AUTO-

2. BAT-

8. Buffer Selection

unit has been calibrated.

3. pH

9. LOCK

This will indicate that the reading i

4. mV

10. EFF -

user is

efficiency value is less than 75%.

5. ATC/MAN

indicator will be displayed.

11. Main display

6. CAL

calibration mode

12. Secondary Display

A. Display

Figure 2

This will be displayed when the
unit is still waiting for a stable

Low Battery Indicator

Unit and mode indicators

Unit and mode indicators.

ATC indicator will be displayed
if a temperature probe is
connected otherwise the MAN

This will be displayed when
the unit enters into the

Auto Lock mode indicator.

This indicator will flash if the
unit is not yet calibrated. This
indicator will remain lit-up if the

during AUTOLOCK mode.

This will be displayed if the
viewing the efficiency of the
electrode. It is recommended to
use a new electrode when the

For pH, mV
and probe efficiency values

Temperature and unit display

5

B. Keys

On/Off

Mode-

“Mode” key to exit the two point calibration mode.

Clear-

that the unit must be calibrated.

Mea. / Eff.-

the LCD will display the efficiency of the electrode.

Press and hold this key for 5 seconds to power on and
shut off the meter. Once the unit is power up, press the
same key to turn on or off the backlight.

Selects display mode. Pressing this key changes the
display sequentially to display pH-AUTO, mV-AUTO, pH
and mV. The calibration values will not be affected by
changing the display modes. In “pH calibration”, press

It is used to clear the unit when error signal appears. It
clears all calibration values stored in the internal
memory.
Under normal use the key will not be activated unless
pressed and held for 2 seconds to prevent accidental
erasing stored memory.
When the Clear key is pressed, all segments of the LCD
will be on. After about 2 seconds the unit will enter the
pH-AUTO mode. The “AUTO” and “CAL” will be on and
one of the buffer values will start to flash. This means

Up/Down-

Increases or decreases the displayed temperature value
when in manual mode, buttons have no effect when in
ATC mode.

Stand/Slope-

The Stand and Slope keys are used for dual or three
point pH calibration of the unit. Pressing and holding
the Stand key while turning on the power, will change
the buffer set to the other available buffer set.

The key is used to bring the unit out of the AUTOLOCK
condition when operating in the pH-AUTOLOCK or mV­AUTOLOCK mode. Press and hold this key for 5 seconds,

6