Adam Equipment CQT-251 Service

@Adam Equipment Company 2011

Adam Equipment

CQT Service

ADAM EQUIPMENT CO. LTD.,

revA, January 2011

@Adam Equipment Company 2011

©Adam Equipment Company 2011

1

CONTENTS

1 CQT

FEATURES ............................................................................................ 3

2 CQT

SPECIFICATIONS................................................................................... 3

3 INTRODUCTION .......................................................................................... 4

4 REMOVING

THE

COVER ............................................................................... 5

5 LOAD

CELL

DAMAGE.................................................................................... 5

5.1 5.1

A/D

COUNTS ................................................................................ 5

6 PRINCIPLE

OF

OPERATION ........................................................................... 7

7 DEALER PARAMETERS .......................................................................... 8

7.1 FILTER.............................................................................................. 8

7.2 ZERO TRACKING RANGE............................................................... 8

7.3 LINEARITY CALIBRATION POINT................................................... 8

7.4 LINEARITY CALIBRATION AMEND VALUE .................................... 9

7.5 CAPACITY ........................................................................................ 9

7.6 DIVISION .......................................................................................... 9

7.7 CALIBRATION WEIGHT................................................................... 9

7.8 CALIBRATION ................................................................................ 10

8 ERROR

MESSAGES ..................................................................................... 10

9 TROUBLE SHOOTING GUIDE............................................................... 12

©Adam Equipment Company 2011

2

©Adam Equipment Company 2011

3

1 CQT

FEATURES

• Auto shut off

• Auto zero tracking

• Auto backlight (optional)

• Low battery indication

• Kg/g/lb/oz/ct/dr/GN/N/tl.t conversion

• Large LCD (6 digits 18 mm high)

• Large square SS pan

• Net weight/stability indication

• Auto calibration

2 CQT

SPECIFICATIONS

Model # CQT-202 CQT- 251 CQT-601 CQT-1501 CQT-2601 CQT-2000 CQT-5000

Maximum

Capacity

200g 250g 600g 1500g 2600g 2000g 5000g

Readability 0.01g 0.1g 0.1g 0.1g 0.1g 1g 1g

Resolution 1:20000 1:2500 1:6000 1:15000 1:26000 1:2000 1:5000

Repeatability

(Std Dev)

0.02g 0.1g 0.1g 0.2g 0.2g 1g 1g

Linearity ± 0.02g 0.1g 0.1g 0.2g 0.2g 1g 1g

Units of

Measure

kg / g / lb / oz / ct / dr / GN / N/tl.t

Stabilisation

Time

3 seconds 2 seconds 3 seconds 2 seconds

Operating

Temperature

0ºC to 40ºC

32ºF to 104ºF

Power Supply 12VAC @ 150mA adapter or 6x AA batteries

Calibration Push button calibration using external mass

Calibration

Mass

100g/

200g

100g/

200g

200g/

400g

/600g

500g/

1000g/

1500g

1000g/

2000g

1000g/

2000g

1000g/300

0g/5000g

Display 6 digit LCD, 18mm digits, with backlight

Draft shield

(diameter x h)

132mm ø x 82mm

(5.2” ø x 3.2”)

N/A

Balance

Housing

ABS Plastic

Pan Size 120mm ø (5.1” ø) 145mm ø (5.7” ø)

Overall

Dimensions

(w x d x h)

173 x 255 x 86mm (6.8” x 10” x 3.3”)

Without draft shield

Net Weight 820g (1.8lb)

©Adam Equipment Company 2011

4

3 INTRODUCTION

The scales are all based on resistance strain gauge load cells. The load

cells output a small voltage in response to a load placed on the weighing

platform. The voltage is in the range of approximately 10mv for a full

capacity load.

The signal from the load cell is presented directly to an A/D converter for

conversion to a digital value for use by the microprocessor.

It may be necessary to replace a load cell if it is damaged.

The load cell connections are:

Before any changes are made to the scale, it will be necessary to

trouble-shoot the problems and determine the best method to solve the

problems. Refer to the Trouble-shooting Guide for suggestions.

High Resolution scales

CQT 202,1501 & 2601

Signal - Black

Signal + Green

Shield Yellow

Ext - White

Ext + Red

Low Resolution scales

All others

Signal - White

Signal + Green

Ext - Black

Ext + Red

©Adam Equipment Company 2011

5

4 REMOVING

THE

COVER

If it becomes required to remove the cover, you should be very careful

as pulling or pressing on the load cell during this procedure can damage

it very easily.

When removing the screws (4 small screws below the scale) hold the

cover to the base and ensure not to press on the balance case as the

load cells can be damaged. The load cell is attached to the base.

The load cells are protected by overload and under-load stops. These

stops are either plates that contact the cover or screws that are

accessible from the outside of the scales.

Refer to the Trouble-shooting Guide for the possible causes of any

problem.

5 LOAD

CELL

DAMAGE

5.1

A/D

COUNTS

Press [Unit] first and then press [On/Off], while keeping the [Unit] key

pressed to enter the dealer parameters. The display will show the

version number and then request passwords.

Press [Unit],[Unit], [Tare], [Unit], [Unit] in sequence to enter the setting

mode.

Press the [Unit] key several times until you enter the calibration settings.

Then you can see the A/D count.

To see the every division A/D counts ,for example: the CQT202 with the

readability 0.01g.

First record the current A/D count, e.g 43860, then put on the 1g weight

to see the new A/D Count ,eg:44198. So the division A/D count is

(44198-43860)/100=3.38. The counts should bigger than 3.

©Adam Equipment Company 2011

6

If the division A/D counts are outside this range or cannot be seen then

it will be necessary to trouble shoot the load cell, load cell connections

to verify the load cell is working correctly and has not been damaged.

The most common reason for a scale to fail is that the load cell has been

damaged. The damage can be due to two primary causes. The first is

the physical damage due to an overload or an impact from the side and

the second is damage due to the environment, such as moisture,

extreme heat or a cut cable if the cables are exposed.

With the CQT scale it is possible the load cell is damaged such that the

scale still operates when the scale is calibrated but not when a small

mass is put on the pan. This will become apparent when the scale reads

correctly at the calibration mass but is not correct at lower masses. The

scale may still zero OK after power is applied but it will not register a

weight value for smaller weights.

Check the A/D counts in this case.

©Adam Equipment Company 2011

7

6 PRINCIPLE

OF

OPERATION

The strain gauge load cell is a method of measuring the amount of stress

put onto a metal structure due to a weight being supported by the

structure. The stress is measured using 4 strain gauge sensors mounted

in a particular way on the metal structure.

These 4 strain gauges are connected in such a way that they form a

Wheatstone bridge. See the figure below. In the simplest load cells

there are only the 4 resistances of the strain gauges to consider.

Normally without a load on the load cell, all the resistances are the

same. However, when the load cell has a weight on it, two of the strain

gauges will be in compression (A and D) and the resistance will decrease

and the other two will be in tension (B and C) and their resistance will

increase.

35

0 o

hm

3

50

ohm

3

5

0

o

h

m

3

5

0

o

h

m

A

B

C

D

+E

-S

-E

+S

BALANCED BRIDGE

10 VOLT POWER

SUPPLY

Vout = O VOLTS,

BETWEEN +S AND -s

3

5

1

o

h

m

3

4

9

o

h

m

3

5

1

o

h

m

3

4

9

o

h

m

A

B

C

D

+E

-S

-E

+S

UNBALANCED BRIDGE

FULL CAPACITY LOAD

ON THE LOAD CELL

10 VOLT POWER

SUPPLY

Vout = 0.028 VOLTS (28mv),

BETWEEN +S AND -s

This will cause the bridge to become unbalanced. When the bridge has a

voltage across it from +E to -E then the signal output at +S and -S will

show a voltage of zero volts with no load and a small voltage

proportional to the load as the load is increased. Typical load cells show

10mv of signal if the excitation voltage is 5volts and the load cell is fully

loaded.

To check the load cell, apply power to the scale and measure a voltage

between the S+ and S- wires when de-soldered from the PCB. The

voltage should be less than 2millivolts with no load on the scale,

increasing as the load is applied. The voltage between the E+ and E-

wires should be 5V.

©Adam Equipment Company 2011

8

7

DEALER PARAMETERS

• Press [Unit] first and then press [On/Off], while keeping the

[Unit] key pressed to enter the dealer parameters. The

display will show “Cqt-1.0 Cqt” “080410 Cqt” and then

request passwords.

• Press [Unit], [Unit], [Tare], [Unit], [Unit] in sequence to

enter the setting mode.

7.1

FILTER

• The display shows “Cqt-1.0 Cqt”and“080410 Cqt”, 1 second

later the balance will enter filter setting and the LCD will

show “X FIL”. “X” is the value for the amount of filtering to

be done. Set a value of 1 to 6. A larger number is more

filtering and a slower response. Default is “1”.

• Press [Tare] key to scroll through the options.

• Press [Unit] to confirm and enter zero tracking range

setting.

7.2

ZERO TRACKING RANGE

• When enter zero tracking range setting, the display will

show “X ZEO”. X is the value for the amount of auto-zero

range. Set a value of 1 to 7. A larger number is a larger

range. Default is “1”.

• Press [Tare] key to scroll through the options.

• Press [Unit] to confirm and enter linearity calibration point

setting.

7.3

LINEARITY CALIBRATION POINT

• This function means setting a point to use in linearity

calibration.

• When enter linearity calibration point setting, the display

will show “X LID”. “X” is the value for point number. Set a

value of 0 to 5. “0” means the point is at 1/3 of capacity, “1”

is 1/2, “2” is 2/3, “3” is 5/6, “4” is 6/7, “5” is 1. Default is

“0”.

• Press [Tare] key to scroll through the options.

©Adam Equipment Company 2011

9

• Press [Unit] to confirm and enter linearity calibration

amend value.

7.4

LINEARITY CALIBRATION AMEND VALUE

• This function means setting a linearity calibration amend

value.

• When enter linearity calibration amend value, the display

will show “X LIN”. “X” is the value for point number. Set a

value of -8 to 8. Default is “0”.

• Press [Tare] key to scroll through the options.

• Press [Unit] to confirm and enter

7.5

CAPACITY

• When enter capacity setting, the display will show “XXXX

CAP”. “XXXX” is the value of the balance capacity. Set a

value of 100g to 6000g.

• Press [Tare] key to scroll through the options.

• Press [Unit] to confirm and enter division setting.

7.6

DIVISION

• When enter capacity setting, the display will show “X.X

CAP”. “X.X” is the value of division. Set a value of 0.002g to

5g. The division you chose must be no less than 1/30000 of

capacity.

• Press [Tare] key to scroll through the options.

• Press [Unit] to confirm and enter calibration weight setting.

7.7

CALIBRATION WEIGHT

• When enter calibration weight setting, the display will show

“XXX WEI”. “XXX” is the value of weight.

• Before calibrating it is necessary to have the proper

calibration weights. The weights should be known to an

accuracy that is appropriate for the balance being

calibrated, for example, OIML Class M1 type or ASTM E617

Class 4. If you do not have proper weights do not attempt

calibration.

• Please choose the weight refer to the form below:

©Adam Equipment Company 2011

10

• Press [Tare] key to scroll through the options.

• Press [Unit] to confirm and enter calibration weight setting.

7.8

CALIBRATION

• Before enter calibration, please make sure the pan is empty.

• When enter calibration, the display will show “XXXXX CAL”.

“XXXXX” is the AD value.

• IF setting for a new PCB it is necessary to press [Tare] to set

the ADC fro a gain of 64 or 128. Set to 128 for the CQT

202,1501 & 2601 or 64 for the others. Press the [Unit] key.

• When the AD value is stabile, press [Unit] key, then “0 LOD”

will be showed on the LCD.

• Put the calibration mass on the pan. The display will show

“XXXXX LOD”. “XXXXX” is the AD value of the mass. When the

value is stabile, press [Unit] key.

• Now calibration is down. The balance will turn to normal

weighting.

8 ERROR

MESSAGES

When power is first applied to the scale a check is made to assure the

A/D counts are within a normal range. If an error is shown at this time

the A/D counts are either too high or too low.

ADO A/D counts at turn on are too high.

ADL A/D counts at turn on are below zero.

In either case, check the A/D counts as described above. Verify the load

cell, load cell wiring and the A/D counts are acceptable. Try to calibrate

the scale if the A/D counts are acceptable.

During normal operation, the display may show an error under these

conditions:

Model CQT-

202

CQT-

251

CQT-

601

CQT-

1501

CQT-

2601

CQT-

2000

CQT-

5000

Calibration

Weight

50g

steps to

max

50g

steps to

max

50g

steps to

max

500g

steps to

max

50g

steps to

max

50g

steps to

max

50g

steps to

max

11

--ERR- User setting error

---ADO A/D value too

high(overload)

---ADL A/D value too low

------ The weight is overload

more than 9 divisions.

Unit-E Unit error

Low battery

PROBLEM POSSIBLE CAUSES

Display is blank Mains power is turned off

No turn on test Power supply not plugged in

Power supply faulty

Display is disconnected or faulty

After turn on test ,Error message is

Displayed

Pan not installed

Unstable weight

Load cell damaged

Display is unstable Drafts or air currents

Obstruction under pan

Sample is moving (animal weighing)

Vibrations through table

Temperature changed dramatically

Power supply faulty

Weight value incorrect Calibration error, Recalibrate

Unit calibrated with inaccurate weight

Balance not level

Obstruction between sample and cover

breeze shield

Wrong unit of weight displayed

Cannot use Full Capacity Over load Stops hitting pan support

hitting bottom of load cell

Shipping screw not removed from base

problem on A/D Load Cell Damaged

Not Linear Overload stops hitting too soon Load cell

damaged

A/D damaged

Capacitor(s) on A/D PCB damaged

Off Center Loading error Overload Stops not correct

Load Cell damaged

Keyboard failure Keys damaged

Cable to display/keyboard not connected

Backlight does not turn on Backlight module damaged

Backlight power supply failed

Incomplete LCD display Poor contacts on LCD

Damaged LCD or circuit board

12

9

TROUBLE SHOOTING GUIDE

13

Manufacturer’s Declaration of Conformity

This product has been manufactured in accordance with the harmonised European standards,

following the provisions of the below stated directives:

Electro Magnetic Compatibility Directive 2004/108/EC

Low Voltage Directive 2006/95/EC

Adam Equipment Co. Ltd.

Bond Avenue, Denbigh East

Milton Keynes, MK1 1SW

United Kingdom

9.1.1.1.1

FCC COMPLIANCE

This equipment has been tested and found to comply with the limits for a Class A digital device,

pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection

against harmful interference when the equipment is operated in a commercial environment. The

equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in

accordance with the instruction manual, may cause harmful interference to radio communications.

Operation of this equipment in a residential area is likely to cause harmful interference in which case

the user will be required to correct the interference at his own expense.

Shielded interconnect cables must be employed with this equipment to insure compliance with the

pertinent RF emission limits governing this device.

Changes or modifications not expressly approved by Adam Equipment could void the user's

authority to operate the equipment.

9.1.1.1.2

WEEE COMPLIANCE

Any Electrical or Electronic Equipment (EEE) component or assembly of parts intended to be

incorporated into EEE devices as defined by European Directive 2002/95/EEC must be recycled or

disposed using techniques that do not introduce hazardous substances harmful to our health or the

environment as listed in Directive 2002/95/EC or amending legislation. Battery disposal in Landfill

Sites is more regulated since July 2002 by regulation 9 of the Landfill (England and Wales)

Regulations 2002 and Hazardous Waste Regulations 2005. Battery recycling has become topical

and the Waste Electrical and Electronic Equipment (WEEE) Regulations are set to impose targets

for recycling.

14

ADAM EQUIPMENT is an ISO 9001:2008 certified global company with

more than 35 years experience in the production and sale of electronic

weighing equipment.

Adam products are predominantly designed for the Laboratory,

Educational, Medical, retail and Industrial Segments. The product range

can be described as follows:

-Analytical and Precision Balances

-Compact and Portable Balances

-High Capacity Balances

-Moisture analysers / balances

-Mechanical Scales

-Counting Scales

-Digital Weighing/Check-weighing Scales

-High performance Platform Scales

-Crane scales

-Medical Scales

-Retail Scales for Price computing

For a complete listing of all Adam products visit our website at

www.adamequipment.com

publication may be reprinted or translated in any form or by any means without

the prior permission of Adam Equipment.

Adam Equipment reserves the right to make changes to the technology,

features, specifications and design of the equipment without notice.

All information contained within this publication is to the best of our knowledge

timely, complete and accurate when issued. However, we are not responsible

for misinterpretations which may result from the reading of this material.

The latest version of this publication can be found on our Website.

www.adamequipment.com

Adam Equipment CQT-251 Service

This manual is also suitable for

Adam Equipment CQT-251 Service

Related papers

Other documents