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GTD-1000Ex

Instruction Manual

6.4. SPAN Calibration

■ Check voltage of 18~31 V DC at both (+24 V) and (GND) of terminal block ‘CN5’.

■ Check whether (mA) terminal of terminal block ‘CN5’ is connected to the receiver.

■ Change DMM to current measuring mode, then connect (+) and (-) terminals or DMM to TP5 (+mA) and 

  TP6(-mA) of AMP PCB, respectively.

■ When span switch (SW6) is pressed for 3 sec, a message "[SP][AN]" flashes 3 times on FND1 and FND2 and 

  it enters span calibration mode.

■ When the standard calibration gas is injected into cell part, 12 mA output is observed. If the output is not 12 mA,  

  adjust the potentiometer 'VR3 (SPAN)' left and right to set 12 mA.

■ Adjust 'SPAN' potentiometer to obtain the correct current output for the standard gas to be displayed on FND1  

  and FND2.

■ When SPAN switch (SW6) is pressed for 4 sec after it is set to a desired output, result from span calibration is   

  displayed on FND1 and FND2. "[PA][SS]" means that the calibration has performed successfully. "[FA][IL]" means  

  that the calibration has not met the condition and failed. In this case, sensor and power must be reconfirmed  

  then calibration shall be performed again.

6.5. Gas Detector Calibration Method using Methane(CH4) Standard Gas

■ Combustible gas sensor used for device can measure various types of combustible gas. However, each combustible  

  gas  has different properties including explosion range, heat generation rate, specific gravity, etc., therefore, it is 

  impossible to perform calibration with every standard gas.

■ Thus, this product uses methane gas as a reference and applies comparative properties of each combustible gas  

  analyzed as shown in the table below.

■ CH4 50% LEL calibration output calculation is as follows.

  Range : 0-100#LEL

  Output signal : 4-20mA

  Calibration Gas: CH4 50% LEL /N2 

  balance Test point signal ( TP5, TP6 )

(200 - 40) ×

  50%LEL (Standard Gas)  

+ 40 = 120 = 12.0mA

                     100%LEL( Full Range)

■ When iso-Butane sensor is calibrated with 2.5% methane standard gas, calculate as shown below. 

  (Explosion range of iso-butane is 1.8% and methane is 5%.)

■ In sensor, it becomes: (100%LEL ÷ 80%LEL) × (2.5% ÷ 5%) × 100%LEL = 62.5%LEL

■ At this time, output from the sensor becomes: 20mA - 4mA) X 0.625 + 4mA = 14mA

Gas Type

Explosion Range (VOL%)

Relative Span LEL%(CH4)

Methane

CH4

5.0

100

Propane

C3H8

2.2

80

iso-Butane

C4H10

1.8

80

n-Pentan

C5H12

1.4

80

n-Hexane

C6H14

1.2

75

n-Heptane

C7H16

1.05

65

iso-Octane

C8H18

0.95

60

Methanol

CH3OH

6.7

130

Ethanol

C2H5OH

3.3

95

iso-Propanol

C3H7OH

2.2

80

Acetone

(CH3)2OH

2.6

85

Toluene

C6H5CH3

1.2

70

Ethyl Acetate

CH3COOC2H5

2.2

75

Hydrogen

H2

4.0

125

Ammonia

NH3

15

150

Cyclohexane

C6H12

1.3

75

Acetylene

C2H2

2.5

35

Ethylene

C2H4

2.7

95

6. Calibration and Maintenance

6. Calibration and Maintenance

[Figure 11. SPAN Calibration related Parts]

Summary of Contents for GTD-1000Ex

Page 1: ...vance d Industry 1 ro Bugok dong Gunpo si Gyeonggi do Tel 82 31 490 0800 Fax 82 31 490 0801 Yeongnam business office Plant 55 Gonghangap gil 85beon gil Gangseogu Busan Metropolitan City Tel 51 973 8518 Fax 51 973 8519 E mail info gastron com www gastron com Read in detail for correct use ...

Page 2: ... a responsibility and give you satisfaction In the present instruction manual operation method for Gas detector as well as simple methods for maintenance and repair etc are recorded If you read it in detail and keep it well for reference when you have questions then it will give you much help The present product and the product manual can be changed without advance notice for performance improveme...

Page 3: ... of Each Part 9 4 1 Components 9 5 Installation 11 5 1 Detachment of Housing Cover 11 5 2 Main PCB Configuration 12 5 3 Power and Signal Terminal Configuration 13 5 4 Method to Connect to External Control Unit 14 5 5 Installation Cable Length 15 6 Calibration and Maintenance 16 6 1 4 20mA Output Diagnosis 16 6 2 Gas Sensor Status Diagnosis 16 6 3 4mA Adjustment ZERO Calibration 17 6 4 SPAN Calibra...

Page 4: ...Cs Ex d llC T6 Basic Interface Analog 4 20mA current interface Option Rain Cover Warranty Transmitter 2Year Sensor 1Year ITEMS SPECIFICATION Explosion Proof type Explosion proof enclosure Dimension 136 W 166 H 95 D mm Weight including Sensor App 1 5kg Mounting type Wall mount Mounting Holes Ø 7 0 1 Cable inlet 3 4 PF 1 2 or 3 4 NPT Body material Transmitter aluminum alloy Sensor Stainless Steel ST...

Page 5: ...nsor Specification Pressure Range 90 to 110KPa Max air velocity 6m s 3 Specification GTD 1000Ex Instruction Manual NO NAME DESCRIPTIONS 1 Detector housing body Protects PCB Board built in Sensor and Housing from external environmental change and shock 2 Detector housing cover It is assembled with detector housing body and protects PCB Board built in Sensor and Housing from external environmental c...

Page 6: ...rew 5 Installation It is prohibited for an individual other than an approved user or a technician responsible for installation and repair from the head office to install a gas leak sensor on site or open the cover of the installed gas leak detector and manipulate it This may cause serious loss of life and property from fire explosion and etc In addition please check whether there is any remaining ...

Page 7: ... Signal Terminal Configuration After disassembling display parts there is a terminal block in the Main PCB as shown in the figure below Holding it with hands and pulling towards ceiling detaches it from the Main PCB Loosen 5 terminal fixing screws located at top part of detached terminal block CN8 VIS mA ETH Connector by turning counter clockwise using a Θ driver Connect DC 18 24 V power to and th...

Page 8: ...g voltage IMAX Max Current of GTD 1000Ex WIRER m The resistance of the wire ohms meter value available in wire manufacturer s specification data sheet Example of installation lengths using 24 V power supply and 16 AWG is as follows GTD 1000Ex minimum operating voltage 18 Vdc VMAXDROP 24 18 6V IMAX 0 2A 200mA 6 0 2 0 01318 2 1138 088m 1138m Figure 6 External Control Unit Connection Method Figure 7 ...

Page 9: ...lashes 3 times on FND1 and FND2 and it enters zero calibration mode When clean air or 99 9 nitrogen N2 is injected to cell part 4 mA output is observed If the output is not 4 mA adjust the potentiometer VR2 ZERO left and right to set 4mA Adjust ZERO potentiometer to obtain a current of 4 00 mA to be displayed on FND1 and FND2 When zero switch SW5 is pressed for 3 sec after output is set to 4 mA re...

Page 10: ... various types of combustible gas However each combustible gas has different properties including explosion range heat generation rate specific gravity etc therefore it is impossible to perform calibration with every standard gas Thus this product uses methane gas as a reference and applies comparative properties of each combustible gas analyzed as shown in the table below CH4 50 LEL calibration o...

Page 11: ... gas leakage is not expected but are easier for leaked gas to stay the detector must be installed at the point 1 of the following Gas leak detector alarm installed outside a building shall be installed at points where gas is likely to stay in consideration to wind direction wind speed specific gravity of gas etc Gas leak detector alarm installed inside a building shall be installed near the floor ...

Page 12: ...ed 5 threads or more Work in conditions satisfying other Standards for Selection Installation and Maintenance etc of Explosion proof Electric Machine and Equipment Wiring etc at Work Site All materials used for cable inlet such as cable gland and sealing fitting etc and used as sealing unused inlets must pass the verification VERSION CONTENTS DATE 0 0 Manual Initial Revision 2013 06 10 1 0 Drawing...

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