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

Electrode Key Features
and Benefits:

• Ryton™ body for chemical compat­ibility with most harsh chemicals.
Also able to withstand high tempera­tures.

• Porous PTFE reference junctions are
highly chemically resistant; resists
fouling and dirt buildup.

• First reference chamber with KNO
protects Ag/AgCl wire for a prolonged
sensor life.

• Capillary TC (temperature sensor)
embedded in tip of pH/ORP electrode
for quicker temperature response
than most other electrodes on the
market.

®

• DryLoc

connector with corrosion
resistant gold pins for quick and easy
sensor removal.

3

Reference
Ag/AgCl
Wire

Double
Porus
PTFE
Reference
Junctions

pH/ORP
Electrode

Electrode Cut-Away View

DryLoc
Connector

Ryton
Body

Reference
Electrolyte
Chamber

st

Reference

1
Chamber with
KNO

Capillary
TC

Model 2774-2777
Ordering Notes:

1) pH and ORP sensors

®

require connection to
model 2750 or 2760.

2) To replace electrodes,
simply twist from pre­amplifier to replace
with new electrode.

™

3) Conduit and mounting
brackets for submers­ible installation must
always be used (cus­tomer supplied).

4) All of these sensors
can be installed up­side-down.

3

5) Special order options
may have longer deliv­ery time. Consult your
local George Fischer
sales representative
for lead times.

2721 Remote Preamplifier

The 2721 remote preamplifier should
be used with special order sensors
that are built with cables (Signet
Models 277X-HT, 277X-1-HT, or other
Signet sensors ordered with cables).
It can also be used for applications
where another manufacturer’s sen­sor is used with a Signet 5700 or 8750
instrument.

43 mm
(1.7 in.)

305 mm
(12.2 in.)

30 mm
(1.2 in.)

Female

BNC

connector

Application Tips:

• Use the flat glass
electrodes when
a self-cleaning
feature is desired;
especially useful in
applications with
abrasive chemicals.

• Use bulb protected
electrodes for
general purpose
applications

• ORP electrodes are
generally used for
chemical reaction
monitoring, not
control.

• Ensure that sen­sor materials are
chemically com­patible with the
process liquid.

94

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Ordering Information

Electrode Part Number- Choose either a pH or ORP Electrode

pH Electrodes

3-2774 Flat pH surface electrode
3-2776 Bulb pH electrode with bulb protection

Temperature Element - Choose one

- 3K Ohm RTD for pH for connection to 8750 or 5700 instruments when used with the 2760 preamplifier.

-1 PT1000 RTD for pH for connection to the 8900 when used with the 2750 sensor electronics

Special Order Options for pH Electrodes - Options -HT and -C can only be used with the 3-2721 preamplifier.
(These options cannot be used with the 2750 or 2760)

-HT

For high temperature and high pressure applications, up to 110°C (230°F) @ 150 psig; DryLoc
tor is removed and replaced with a 4.6m (15 ft.) cable.

-C Remove DryLoc

-ISO ISO 7/1 R - 3/4 Threaded electrodes are available.

ORP Electrodes

3-2775 Flat ORP surface electrode
3-2777 Bulb ORP electrode with bulb protection

Temperature Element - Choose one

- 10 K ID resistor for ORP electrodes for connection to the 8750 and 5700 when used with the 2760 preamplifier
or the 8900 when used with the 2750 sensor electronics

-1 No T.C. for ORP electrodes for use with other suppliers instruments when used with the 2760 connector
Special Order Options for ORP Electrodes - Options -HT and -C can only be used with the 3-2721 preamplifier

(These options cannot be used with the 2750 or 2760

-HT

For high temperature and high pressure applications, up to 110°C (230°F) @ 150 psig; DryLoc
tor is removed and replaced with a 4.6m (15 ft.) cable.

-C Remove DryLoc

-ISO ISO 7/1 R - 3/4 Threaded electrodes are available.

3-2775 Example Part Number

®

connector and add 4.6m (15 ft.) cable. Other cable lengths are available

®

connector and add 4.6m (15 ft.) cable. Other cable lengths are available

®

connec-

®

connec-

Choosing

Products

Instrument

Multi-Pa-

rameter

Flow

pH/ORP

Conductivity/

Resistivity

Pressure, Level

Temperature,

Preamplifiers & Sensor Electronics - Choose one (required for initial installation of any pH or ORP electrode)

The Sensor Electronics below can be used with the Signet 8900 or as a blind transmitter with 4 to 20 mA output for connec­tion to a PLC, PC, chart recorder, and other devices requiring 4 to 20 mA input.

3-2750-1 In-line Sensor electronics w/junction box
3-2750-2 In-line Sensor electronics w/junction box and EasyCal
3-2750-3 Submersible Sensor electronics w/4.6m (15 ft) cable and 3/4 in. NPT threads
3-2750-4 Submersible Sensor electronics w/4.6m (15 ft) cable and 3/4 in. ISO threads

The Preamplifiers below can be used with the Signet 5700 or 8750 Instruments

3-2760 pH/ORP Preamplifier (for use with the 8750 or 5700 instrument) or Connector (for use with other manufacturer’s

3-2760 -2 1 Example Part Number

instruments) with 4.6m (15ft.) cable
Preamplifier or Connector Style; Choose one

-1 Preamplifier with 3/4 inch NPT threads

-2 Preamplifier with 3/4 inch ISO threads

-3 Connector with 3/4 inch NPT threads

-4 Connector with 3/4 inch ISO threads

Mounting Configurations; Choose one

- Submersible mounting - gray body
1 In-line mounting - yellow body

Mfr. Part No. Code Mfr. Part No. Code Mfr. Part No. Code Mfr. Part No. Code

3-2774 159 000 955
3-2774-1 159 000 956
3-2775 159 000 957
3-2775-1 159 000 958

3-2776 159 000 959
3-2776-1 159 000 960
3-2777 159 000 961
3-2777-1 159 000 962

3-2750-1 159 000 744
3-2750-2 159 000 745
3-2750-3 159 000 746
3-2750-4 159 000 842

3-2760-1 159 000 939
3-2760-2 159 000 940
3-2760-3 159 000 941
3-2760-4 159 000 942
3-2760-11 159 001 367
3-2760-21 159 001 368
3-2760-31 159 001 369
3-2760-41 159 001 370

Accessories and Replacement Parts

Mfr. Part No. Code Description

3-0700.390 198 864 403 pH Buffer kit (includes pH 4.0, 7.0, and 10.0
buffer powder)
3-2759 159 000 762 pH/ORP System Tester
3-2759.391 159 000 764 Adapter Cable for use with 2750/2760
3-2721 198 864 610 Remote mount pH/ORP preamplifier

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Please refer to Wiring,
Installation and
Accessories sections for
more information

95

Products

Other

Installation

Wiring &

Reference

Technical

Temperature/

Pressure

Graphs

of Terms

Glossary

Reference

Part No.

Index