Georg Fischer 2774-2777 Operating Manual

Signet 2774-2777 Threaded DryLoc® pH/ORP Electrode

4

Features

• Durable DryLoc®
connector with gold
plated contacts

• Special design allows
for installation at any
angle, even inverted

• Quick temperature
response

Flat Glass

Description

The Signet 2774 - 2777 pH and ORP
Electrodes feature a unique foul-

®

proof DryLoc

connector with gold­plated contacts designed specifically
for use with the Signet 2750 and 2760
preamplifiers, sensor electronics,
and connectors. These dependable
and highly responsive electrodes fea­ture a PTFE double reference junc­tion and a large reference chamber
that combine to extend the service­life. Embedded positioning of the
temperature element in the pH/ORP
sensing tip allows the temperature

System Overview

In-Line Installation

Panel Mount

Signet Instrument
(sold separately)
5700 8750 8900

Signet 2750 or
Signet 2760
(sold separately)

4 to 20 mA Input

Chart Recorder

Programable

PLC

Signet 2750
(sold separately)

Controller

OR

Logic

Pipe, Tank or Wall Mount

Signet Instrument
(sold separately)
8750

Signet
Universal
Adapter Kit
(3-8050)
(sold separately)

Signet 2760
(sold separately)

Protected Bulb

response to be quick and accurate.
The electrodes are offered with either
flat or bulb style sensing elements.
The flat versions allow sediment and
particles to sweep past the measure­ment surface, minimizing risks of
abrasion, breakage and coating. The
bulb versions can be used for gen­eral-purpose applications. Due to the
specially designed chambers which
keep electrolyte in place, all versions
can be installed at any angle, even
inverted.

Submersible Installation

Other Instruments

Customer supplied

Flow

Signet 2760
(sold separately)

Panel, Pipe, Tank, Wall Mount

678

RELAY 2

10

RELAY 1

pH

12

2

14

0

ENTER

+GF+

SIGNET

Signet or Other Instrument

5700 8750 8900

Pipe extension
or conduit with
3/4 in. FNPT
threads
(customer supplied)

Signet 2750 or
Signet 2760
(sold separately)

• Easy sensor replace-

®

ment using DryLoc
electrode connector

• High temperature
versions available

• Mounts into standard
3/4 inch threads

• Compatible with all
Signet pH/ORP instru­ments

Applications

• Water Treatment &
Water Quality

Monitoring

• Demineralizer, Re­generation & Rinse

• Cooling Tower and
Boiler Protection

• Aquatic Animal Life
Support Systems

• Pool and Spa Control

• Neutralization

Systems

Signet 2774-2777
DryLoc pH/ORP Electrodes

Fittings - Customer supplied

92

Signet 2774-2777
DryLoc pH/ORP
Electrodes

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Dimensions Specifications

38.6mm
(1.52 in.)

35.5mm
(1.4 in.)

29.2mm
(1.15 in.)

128.3mm
(5.05 in.)

22.8mm
(0.9 in.)

22.1mm
(0.87 in.)

General

Compatibility:
Signet Models 2750 and 2760
Operating Range:

• 2774/2776: 0 to 14 pH

• 2775/2777: +/-2000 mV (ORP)
Pipe Size Range: 1 inch and up.

Reference:
Electrolyte:
KNO

/KCI acrylamide gel

3

Element: Ag/AgCl

Primary Functions:

• 2774 and 2775:

3/4 in.
NPT

Flat surface resists fouling

• 2776 and 2777:
Bulb surface for general use

Wetted Materials:

• Body: Ryton™

• Reference junctions: PTFE

• Sensing surface:
Glass membrane: (pH)
Platinum: (ORP)

• O-rings: FPM

Mounting:

• In-line/vertical mounting: Use the
electrode’s 3/4 in. threads to install
into pipe fitting. Electrode can be
mounted at any angle.

• Submersible mounting: Use
threads on Model 2750 or 2760;
requires 3/4 in. NPT or ISO7-R/ 3/4
in. male threaded extension.

Temperature Sensor:

• pH: 3KΩ or PT1000 RTD

• ORP: none

Temperature response time:
τ

< 1 min.

95%

Shipping Weight: 0.25 kg (0.55 lbs.)

Standards and Approvals

• CE

• Manufactured under ISO 9001:2000
for Quality and ISO 14001:2004 for
Environmental Management

Choosing

Products

Instrument

Multi-Pa-

rameter

Flow

pH/ORP

Conductivity/

Resistivity

Pressure, Level

Temperature,

Max. Temperature/Pressure rating:

Operating Temperature:
0°C to 85°C (32°F to 185°F)
Maximum Operating Pressure:

6.9 bar (100 psi)
Storage Temperature:
> 0°C (32°F)
Higher temperature and pressure sen­sors are available.

Model 2774-2777 Compatibility Selection Chart for Electronics and Instruments

Compatible Signet Instruments

Sensor Temp.

2774 3 KΩ 2760-1, -2,

2774-1 PT 1000

2775 10 KΩ 2760-1, -2,

2775-1 None - - - - 2760-3, -4, -31, or -41 2760-1, -2, -11, or -21
2776 3 KΩ 2760-1, -2,

2776-1 PT 1000

Compatible Electrodes

2777 10 KΩ 2760-1, -2,

2777-1 None - - - - 2760-3, -4, -31, or -41 2760-1, -2, -11, or -21

*Must have internal preamplifier in instrument
**Must use sensor with compatible temperature element; contact technical service for questions

Element

5700 8750 8900 PLC

-11, or -21

-11, or -21

-11, or -21

-11, or -21

2760-1, -2,

-11, or -21

--

2760-1, -2,

-11, or -21

2760-1, -2,

-11, or -21

--

2760-1, -2,

-11, or -21

--

any 2750 w/
digital output

any 2750 w/
digital output

--

any 2750 w/
digital output

any 2750 w/
digital output

any 2750 w/4 to
20 mA output

any 2750 w/4 to
20 mA output

any 2750 w/4 to
20 mA output

any 2750 w/4 to
20 mA output

Other Mfr’s Instruments with
internal preamplifiers*

2760-3, -4, -31, or -41 2760-1, -2, -11, or -21

2760-3, -4, -31, or -41 2760-1, -2, -11, or -21

2760-3, -4, -31, or -41 2760-1, -2, -11, or -21

2760-3, -4, -31, or -41 2760-1, -2, -11, or -21

2760-3, -4, -31, or -41 2760-1, -2, -11, or -21

2760-3, -4, -31, or -41 2760-1, -2, -11, or -21

Other Mfr’s Instruments requiring
external preamplified signals**

Products

Other

Installation

Wiring &

Reference

Technical

Temperature/

Pressure

Graphs

of Terms

Glossary

Reference

Part No.

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Index

93