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AN-78

SS ZMT

General Information

The ZMT Zirconia Indicating Transmitter/Alarm Unit is a
versatile microprocessor based oxygen analyzer designed
primarily to meet the requirements of the boiler market,
utilizing zirconia oxygen probes for energy management.

The ZMT is suitable for use with two types of zirconia oxygen
probe (ZFG2 and ZGP2) and can be provided in standard and
advanced efficiency form.

The standard analyzer has high/low alarms and isolated
retransmission. Display features include probe mV, probe
temperature, cell constant, retransmission range, cell
'warming up' indication with high/low cell fault indication,
thermocouple failure fault indication, a provision to measure
cell impedance, calibration of cell using test gases and the
ability to display a calculated inferred CO

value. The standard

unit also accepts inputs of probe mV and thermocouples, with
the facility to program a temperature for use when the probe
has no thermocouple of its own, but the operating temperature
is known.

The standard analyzer provides oxygen readout with
computation based on the probe output voltage. The voltage
output is Nernstian in form and follows the equation:

P

0

E(mV) =

0.0496 T (log

10

 ––– ) ±C (mV)

P

1

Where

T

=

Absolute temperature (°K)

P

0

=

Partial pressure reference gas

(air)

P

1

=

Partial pressure sample gas

C

=

Cell constant

0.0496 =

Faraday's Gas Constant

The advanced analyzer, in addition to the facilities offered by
the standard analyzer, provides an efficiency calculation
readout by application of the Siegert formula:

K(T

1

 – T

2

)

Efficiency =100 – –––––––––

20.8 – %O

2

where T

1

= Flue temperature (at economizer or boiler

output)

T

2

= Inlet air temperature

%O

2

= Measured %O

2

 in flue gas

K

= Fuel constant dependent on fuel type

e.g.

Natural gas

K = 0.66

Fuel oil

K = 0.70

Bituminous coal K = 0.73

The efficiency is displayed as a percentage with the facility to
display inlet air temperature and flue gas temperature as
required.

The ZMT can accept a carbon monoxide signal transmitted
from another analyzer unit. This signal can be displayed as
'ppm CO'.

The ZMT compensates for process temperatures in the range
of 600°C to 1400°C (1112° to 2552°F) when used with the
ZGP2 probe. The temperature of the probe heater is
automatically controlled by the ZMT when used with the ZFG2
zirconia probe.

Probe reference air supply is available, either through pump
units or by use of an air regulator operated from the
customer's instrument air line.

Construction and Operation

The ZMT zirconia analyzer is housed in a sheet steel
enclosure, environmentally protected to IP55, having a hinged
front door fitted with a 15 button tactile membrane switch
panel and display window.

There are two blue-filtered, vacuum fluorescent displays
visible through the door window. The upper, five-digit display is
used for monitoring process values. The lower 20-character
dot matrix display is used during setting, operating and
programming.

Membrane switches on the ZMT unit include %O

2

,

temperature, alarm, efficiency, CO

2

/CO and calibration. The

%O

2

, efficiency and CO

2

/CO switches are dedicated push

buttons, i.e. when depressed only the required monitored
value displayed. The units of measurement are indicated on
the dot matrix display.

Temperature, alarms and calibration switches, in conjunction
with the  

Å

 switch, permit programming and setting up of the

various parameters for system operation. Additional pages
are available through operation of the 

É

 switch such as the

Analog Retransmission page, the Relay Allocation page,
Diagnostic page and Commissioning page.

Two levels of security are provided to protect various stages of
the programming. The first involves operation of the front
panel switches, the second, more secure, is an internal
switch.

Single fuel and dual fuel boiler operation is monitored by
programmable selections from seventeen different fuel types.
On dual boilers fuel changeover is implemented either
manually of automatically.

The instrument uses a CMOS 6303 microprocessor, a switch
mode power supply with pulse width modulation circuitry for
analog retransmission and offers up to three analog outputs
(isolated) plus up to four relay outputs in combinations of up to
six outputs total.

SUNSTAR传感与控制 http://www.sensor-ic.com/ TEL:0755-83376549 FAX:0755-83376182E-MAIL: [email protected]

SUNSTAR自动化 http://www.sensor-ic.com/ TEL: 0755-83376489 FAX:0755-83376182 E-MAIL: [email protected]

Summary of Contents for ZMT Zirconia

Page 1: ...for maximum flexibility Two levels of program security to reduce accidental changes High levels of accuracy resolution and RFI immunity CEGB approved ZMT Zirconia Oxygen Analyzer Systems ABB Instrumentation SUNSTAR传感与控制 http www sensor ic com TEL 0755 83376549 FAX 0755 83376182E MAIL szss20 163 com SUNSTAR自动化 http www sensor ic com TEL 0755 83376489 FAX 0755 83376182 E MAIL szss20 163 com ...

Page 2: ...the range of 600 C to 1400 C 1112 to 2552 F when used with the ZGP2 probe The temperature of the probe heater is automatically controlled by the ZMT when used with the ZFG2 zirconia probe Probe reference air supply is available either through pump units or by use of an air regulator operated from the customer s instrument air line Construction and Operation The ZMT zirconia analyzer is housed in a...

Page 3: ...ha 16 Anthracite 08 Kerosene 17 Coke Basic Type Ref Probe Type Ref Air Supply See Note 2 Probe Temp Control Fuel Option See Note 1 Efficiency Unused Output Module 1 Output Module 2 Output Module 3 Mains Voltage Code Digit Nos 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ZMT 1 ZGP2 0 1 4 None Pump Air Gauge Regulator 0 None 1st 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 2nd 00 01 02 03 04 05 0...

Page 4: ...r 230V 15 50 60Hz Power consumption 150VA Insulation mains to earth line to ground 2kV r m s Outputs and Set Points Analog outputs isolated 0 to 10mA 0 to 20mA or 4 to 20mA up to three max into 1kΩ max load Output Modules 1 and 2 programmable O2 any range 5 min span within the range of 0 to 25 O2 i e dual ranging possible Temperature any range 200 C 392 F min span within the ranges Cell temp 0 to ...

Page 5: ...ases are in contact with the outer electrode producing a potential proportional to O2 concentration The Probe The zirconia probes constructed from 316 stainless steel house a ceramic dust filter and flame trap the detector cell cell heater and thermocouple Wiring between the electronics unit and the probe can be carried in a single 6m 20ft flexible conduit which is PVC coated for IP65 NEMA4 rated ...

Page 6: ... certified test gas Flue Temperature 20 to 600 C 68 to 1112 F Pressure Suitable for all normal positive or negative flue pressures Dimensions See dimension details diagram Probe Fixing Flange or 21 2 in NPT screwed fitting ZFG2 0 4m Probe Insertion 0 4 1 0 1 5 or 2 0m standard Specials up to 4 0m max Flange Options 0 4m ZFG2 Standard 6 0 0 4 thick x 101 0 1 dia 6 holes 7 3 dia equispaced on 80 0 0...

Page 7: ...erature compensation to be made A gas calibration port is provided to enable the probe output to be checked using test gas mixtures without removal from the process Reference air is required for accurate operation Principle of Operation The detector cell is constructed from stabilized zirconia with inner and outer electrodes attached and is specific to oxygen Air is supplied to the inner reference...

Page 8: ...ted NiCr NiAl or Pt Pt 13 Rh Thermocouple Pt Pt 13 Rh Pt 2 BS4937 Type R NiCr NiAl Pt 4 BS4937 Type K Insertion Length 556mm 21 9in or 953mm 37 5in Weight 2 5kg 5 5lb nett 600mm 24in probe 2 8kg 6 16lb nett 1000mm 39in probe Code Digits Insertion Length Thermocouple Sheath Mounting Connector Head 1 2 3 4 6 7 8 9 10 ZGP2 Zirconia Oxygen Probe 1 2 9 600mm 24in 1000mm 39in Special 1 2 9 Pt Pt13 Rh BS...

Page 9: ...Efficiency see Note 1 UNUSED 12th character 0 None OUTPUT MODULE 1 13th character 0 None 4 Analog relay OUTPUT MODULE 2 14th character 0 None 1 One relay 4 Analog relay OUTPUT MODULE 3 15th character 0 None 1 One relay 2 Two relays Required with 11 th character 3 or 4 4 Analog Relay Not available with Probe ZGP see Note 2 MAINS VOLTAGE 16th character 1 110V 50 60 Hz 2 230V 50 60 Hz ZMT231000001400...

Page 10: ...Instrumentation Inc ABB Kent Taylor SpA St Neots Cambs P O Box 20550 22016 Lenno England PE19 3EU Rochester New York 14602 0550 Como Italy Tel 01480 475321 Tel 716 292 6050 Tel 0344 58111 Fax 01480 217948 Fax 716 273 6207 Fax 0344 56278 SUNSTAR传感与控制 http www sensor ic com TEL 0755 83376549 FAX 0755 83376182E MAIL szss20 163 com SUNSTAR自动化 http www sensor ic com TEL 0755 83376489 FAX 0755 83376182 ...

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