A D GXA-13 Density Determination Kit Instruction Manual

: June 9, 2024
: A D

Table of Contents

GXA-13 Density Determination Kit
Read User Manual Online (PDF format)
Download This Manual (PDF format)

GXA-13 Density Determination Kit

GXA-13 Density Determination Kit
1WMPD4003565B

© 2017 A&D Company, Limited. All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, or translated into any language in any form by any means without the written permission of A&D Company, Limited.
The contents of this manual and the specifications of the instrument covered by this manual are subject to change for improvement without any notice and obligation on the part of the manufacturer.

Contents

1. Introduction…………………………………………………………………………………………………………………………..4 1.1. Precautions………………………………………………………………………………………………………………………4

2. Packing List ………………………………………………………………………………………………………………………….5

3. Density Measurement Principle……………………………………………………………………………………………..6 3.1. Density …………………………………………………………………………………………………………………………….6 3.2. Specific Gravity…………………………………………………………………………………………………………………6 3.3. Density Measurement Principle …………………………………………………………………………………………6 3.4. Density of a Solid………………………………………………………………………………………………………………6 3.5. Density of a Liquid…………………………………………………………………………………………………………….6

4. Error Factors…………………………………………………………………………………………………………………………7 4.1. Buoyancy of Air…………………………………………………………………………………………………………………7 4.2. Temperature of a Liquid …………………………………………………………………………………………………….7 4.3. Volume of Float…………………………………………………………………………………………………………………7 4.4. Influence of Wire……………………………………………………………………………………………………………….7 4.5. Surface Tension………………………………………………………………………………………………………………..8 4.6. Bubbles……………………………………………………………………………………………………………………………8

5. Measuring the Density of a Solid ……………………………………………………………………………………………9 5.1. Assembling the Kit…………………………………………………………………………………………………………….9 5.1.1. Assembling the Kit Using Glass Breeze Break (GXA-10) ……………………………………………..10 5.2. Measuring the Density of a Solid………………………………………………………………………………………11 5.2.1. Density of Water…………………………………………………………………………………………………………11

6. Measuring the Density of a Liquid…………………………………………………………………………………………12 6.1. Assembling the Kit…………………………………………………………………………………………………………..12 6.2. Measuring the Density of a Liquid…………………………………………………………………………………….12

Density Measurement Using the GX-AGF-ABalance…………………………………………………………………….13

7.1. Preparation Before Measurement (Settings of the Function Table…………………………………..14

7.2. Measuring Solid Density (Specific Gravity), Function Table ……………………………………….20

7.3. Specifying Liquid Density…………………………………………………………………………………………………23

7.4. Measuring Liquid Density (Specific Gravity), Function Table ……………………………………..26

7.5. Specifying Volume of Float ………………………………………………………………………………………………29

8. Frequently Asked Questions and Answers……………………………………………………………………………31

3

1. Introduction
Thank you for your A&D purchase! This is the instruction manual for the density determination kit. The density determination kit can be easily used to measure the density of solid or liquid when it is combined with the following electronic balances. GX-203A, GX-303A, GX-403A, GX-603A, GX-1003A, GX-1603A, GF-203A, GF-303A, GF-403A, GF-603A, GF-1003A, GF-1603A Before using the density determination kit, please read this instruction manual thoroughly.
1.1. Precautions
This density determination kit allows the density or specific gravity of a solid or liquid to be measured. However, the results of measurements may be affected by various factors that could cause errors, therefore we cannot guarantee them to be 100 % accurate. Do not use the density determination kit for measuring the density of chemically active substances. After using the density determination kit, clean all surfaces to remove rust and oxides. The balance is precision instrument, so avoid shocks or excessive loads. To improve measuring accuracy, allow the temperature of liquid (water) and sample (solid) to equalize to the ambient room temperature and perform measurement in a stable environment. The breeze break provided with the balance cannot be used with the density determination kit. To perform an accurate density measurement, use the glass breeze break available as an option ( GXA-10).
4

2. Packing List

Float

0.2 Wire

Float hook

Thermometer

Density pan stand

Beaker stand

Beaker

Thermometer clamp

Density pan

Beaker stand spacer 2 pieces

Kit box

Tweezers

5

3. Density Measurement Principle

3.1. Density

Density means the amount of mass of a sample per unit volume. ( Unit [g/cm3] and others )

=

M V

: Density [g/cm3] M: Mass [g]

V: Volume [cm3]

3.2. Specific Gravity

Specific gravity means the ratio of the density of a sample to the density of pure water (with the same

volume as that of the sample) at 4 °C at 1013.25 hPa.

=

M V·4

: Specific gravity [ No unit ] M: Mass [g]

V: Volume [cm3]

4: Density of water at 4 [°C], 0.99997 [g/cm3] 1.000 [g/cm3]

3.3. Density Measurement Principle
The GXA-13 combined with an authorized balance can measure the density of a sample based on the Archimedes’ principle.
Archimedes’ Principle of Density Measurement A body immersed in a liquid (gas) is subject to an upward force equal to the weight of the liquid (gas) it displaces. The upward force is buoyancy.

3.4. Density of a Solid

The density of a solid can be obtained according to the sample weight in air, sample weight in liquid

and the density of the liquid.

=

A A – B

×0

: Density of sample [g/cm3] 0: Density of liquid [g/cm3]

A: Sample weight in air [g] B: Sample weight in liquid [g]

3.5. Density of a Liquid

The density of a liquid can be obtained according to the weight of the float in air, the weight of the

float in a liquid, and the known volume of the float.

=

A – B V

+d

: Density of liquid [g/cm3] V: Volume of the float [cm3]

A: Weight of the float in air [g] B: Weight of the float in liquid [g]

d: Density of air ( approximately 0.001 [g/cm3] )

6

4. Error Factors
There are several error factors that may affect the accuracy of a density measurement.

4.1. Buoyancy of Air

When the liquid density is measured, an upward force, 0.0010 to 0.0014 [g/cm3], is exerted in proportion to the volume of the liquid. The buoyancy in air per 1 [cm3] is found by:

d

=

0.0012932 1+0.0036728×t

×

P 1013.25

d: Air density [g/cm3] P: Air pressure [hPa]

t: Air temperature [°C]

When obtaining measurement results down to the third decimal place, 0.001 [g/cm3] is added to the measured value to compensate for an error in air density.

4.2. Temperature of a Liquid
When taking a density measurement using a liquid, the density measurement will change depending on the temperature. Obtain the density of a liquid by comparing its temperature with the values in “Table 1 Temperature and Density of Water” for distilled water or provided in other reference documents for other liquids.

4.3. Volume of Float
The tolerance of the measured value of the volume of the float is ±0.01 [cm3].

4.4. Influence of Wire
When a solid sample is placed on the density pan for measurement, which is immersed in a liquid, the liquid surface position rises. At this time, the wire (1 mm) connecting the upper and lower pans is subject to the buoyancy whose magnitude is equal to the weight of the raised liquid. 1 mm raise of the liquid surface exerts a buoyancy of approx. 0.8 mg to the wire. To minimize a measurement error caused by the buoyancy, adjust the sample size so that it will not raise the liquid surface, or perform a mathematical correction.
When measuring the density of a liquid, the float-suspending wire (2 mm) immersed in the liquid affects the measurement. Immersing the wire by 10 mm exerts a buoyancy of approx. 0.3 mg to the wire. However, this buoyancy can be ignored because it is divided by the volume of the float when the density of the liquid is obtained.

7

4.5. Surface Tension
When the density of a solid is measured, a force of approx. 5 mg (surface tension) is applied to the density pan, between the wire (1 mm) of the density pan and the surface of the liquid. The surface tension can be reduced to approx. 1 mg by adding a surfactant (for example, a water droplet preventive solution as used for developing photographs). Adding 0.1 mL (1.2 [g/cm3] density) of a surfactant to 200 mL of water will increase the density of the water by approx. 0.0001 [g/cm3]. When the density of a liquid is measured, a force of about 1 mg is exerted by the wire of 0.2 mm in diameter. However, this force can be ignored because it is divided by the volume of the float.
4.6. Bubbles
The buoyancy of a bubble of 1 mm in diameter is approx. 0.5 mg. Stickiness of bubbles depends on the shape and material of a sample. Make measurements considering the characteristic of bubbles. When the density of a solid is measured, we recommend adding a surfactant to reduce the influence of surface tension and bubbles.
8

5. Measuring the Density of a Solid
5.1. Assembling the Kit

Step 1. Remove the weighing pan and breeze break from the balance.

LiquidStep 5. Step 4.

Step 2. Put the density pan stand on the pan support.

Step 3. Place the spacer under the legs of the beaker

Beaker

stand so that the legs fit to the ditch of the

spacer. Put the beaker stand on the balance as such

Step 5.

that it will not touch the density pan stand.

Step 4. Attach the thermometer clamp to beaker.

Spacer to prevent slipping

Insert the thermometer into the clamp.

Weighing pan

Step 5. Pour a liquid (distilled water, etc.), whose

specific gravity is known, into the beaker. Put the beaker on the beaker stand.

Step 1.

Thermometer Thermometer clamp
Beaker stand Density pan
Step 6.
Step 3.
Density pan stand Step 2.
Pan support

Step 6. Place the density pan on the density pan stand.

Step 7. Adjust the amount of the liquid so that sample is approximately 10 mm under the surface of the liquid when the sample is put on the lower pan of the density pan in the liquid.
Step 8. Press the RE-ZERO key to display zero after the weighed value stabilized. All preparations are complete.

Step 7. Adjust liquid surface.
Approx. 10 mm Sample Lower pan

If the weighing value is unstable due to breeze

and vibration, etc., increase the parameter of

“Condition (

)” in the function table or

use the breeze break.

9

5.1.1. Assembling the Kit Using Glass Breeze Break (GXA-10)

Step 1. Remove the weighing pan from the balance.

Step 2. Place the breeze break on the balance and perform the procedures from step 2 to step 8 in “5.1. Assembling the Kit”. All preparations are complete.

If the weighing value is unstable due to breeze

and vibration, etc., increase the parameter of

“Condition (

)” in the function table or

use the breeze break.

10

5.2. Measuring the Density of a Solid

The density of a solid can be obtained by averaging the measured values. Display example is GX-603A.

Step 1. Start the measurement after the water temperature becomes stable.

Step 3. Sample

Step 2. Press the RE-ZERO key to display zero.

Step 2.

Step 3. Put sample on the upper pan of the density pan and record the measurement value A in air.

Step 4. After removing the sample from the upper pan of the

density pan, press the RE-ZERO key to display

zero.

Put the sample on the

lower pan after step 4. Step 5. Put sample on the lower pan of the density pan

and record measurement value B in liquid. Step 5. Adjust liquid surface.

Adjust the amount of the liquid so that

Approx. 10 mm

sample is approximately 10 mm under the Sample

liquid surface when the sample is put on

Lower pan

lower pan in the liquid.

Step 4.

Step 6. Obtain the water density using the water temperature and

“Table-1, temperature and density of water”. Acquire liquid density

using the following formula substituted the measured value.

=

A A – B

x 0

: Calculated sample density [g/cm3] 0 : Water density [g/cm3] A : Measurement value in air [g]

B : Measurement value in water [g]

Example of recording sheet and calculation (3 significant figures).

Measurement value in air A

4.810 [g]

Measurement value in water B

4.215 [g] Water temperature 26 °C

Water density 0 0.99678 [g/cm3] Calculated sample density 8.06 [g/cm3]

4.810 4.810 4.215 x 0.99678 = 8.06 [g/cm3]

5.2.1. Density of Water

At sea level (1 atmosphere pressure), the density of water reaches a maximum at 3.98 [°C].

Table 1, Temperature and Density of Water

Unit: g/cm3

°C +0

+1

+2

+3

+4

+5

+6

+7

+8

+9

0 0.99984 0.99990 0.99994 0.99996 0.99997 0.99996 0.99994 0.99990 0.99985 0.99978

10 0.99970 0.99961 0.99949 0.99938 0.99924 0.99910 0.99894 0.99877 0.99860 0.99841

20 0.99820 0.99799 0.99777 0.99754 0.99730 0.99704 0.99678 0.99651 0.99623 0.99594

30 0.99565 0.99534 0.99503 0.99470 0.99437 0.99403 0.99368 0.99333 0.99297 0.99259

40 0.99222 0.99183 0.99144 0.99104 0.99063 0.99021 0.98979 0.98936 0.98893 0.98849

11

6. Measuring the Density of a Liquid

6.1. Assembling the Kit
Assemble the kit as described in the procedure below.
Step 1. Refer to “5.1. Assembling the Kit” up to assembling the beaker stand.
Step 2. Attach the thermometer clamp to beaker. Insert the thermometer through this clamp.

The volume of the float is stamped on the hook. Ex. 10.01 cm3
Step 4. Length is approximately 50 mm

Step 3. Put the beaker on the beaker stand.

Step 5. Hook of the float

Step 4. Connect the float and hook using stainless wire whose length is approximately 50 mm.
Step 5. Hang the hook to density pan stand. Check that it does not hit the beaker, and lower the float.

Float
Density pan stand Beaker stand

Step 6. This completes the preparations before measurement.

6.2. Measuring the Density of a Liquid
The density of a liquid can be obtained by the following procedure. Display example is GX-603A. Step 1. Press the RE-ZERO key to set the displayed value to zero.

Step 2. Place the float, and then record its weight in the air. Let the measured value be A.

Step 3. To measure density of the liquid, pour it into the beaker. Adjust the amount of the liquid so that the sample is approximately 10 mm under the liquid surface when the sample is hung in the liquid.

Step 4. When the display stabilizes, and then record its weight of the float in the liquid. Let the measured value be B.

Step 5. Use the following equations to obtain the density of the liquid.

: Calculated density of liquid [g/cm3]

= A – B + d A : Weight of float in air [g]

V

B : Weight of float in liquid [g]

V : Volume of float (stamped on the hook) [cm3]

d : Density of air (Approximately 0.001 [g/cm3])

Example of recording sheet and calculation (3 significant figures).

Liquid surface Approx. 10 mm Step 3. Float

Measurement value A – B

9.970 g

Volume of float V

10.01 cm3

Density of air d 1.184×10-3 g/cm3

Temperature 25 °C Atmospheric pressure 1013.25 hPa Calculated density of liquid 0.997 g/cm3

9.970 10.01 + 0.001 = 0.997 [g/cm3] 12

7. Density Measurement Using the GX-AGF-A Balance
The GX-A / GF-A balances are equipped with a density function (specific gravity mode). When this density determination kit GXA-13 is used with density function of the following balances, the density of a solid and liquid can be measured. GX-203A, GX-303A, GX-403A, GX-603A, GX-1003A, GX-1603A, GF-203A, GF- 303A, GF-403A, GF-603A, GF-1003A, GF-1603A

Caution

The density function (

) of the balance cannot be selected when using factory

settings.

The density function of the balance does not display in the function table when the specific gravity

( ) of the weighing unit (

) is inactive. To use the specific gravity of the weighing

unit, register “specific gravity” of “weighing unit” in the “function table” at first, and then select the

specific gravity ( ) of the weighing unit using the MODE key in weighing mode.

When the liquid density input (

) is active, the liquid density input (

) or density of solid

( ) is displayed. Refer to the instruction manual of balance for operation method of the “function

table”.

The measurement value of density (specific gravity) is fixed to 3 decimal places.

13

7.1. Preparation Before Measurement (Settings of the Function Table
Set the function table of the balance before the density function (specific gravity mode) is used.

Enabling the Unit of Specific Gravity ( ) Register the specific gravity ( ) of the weighing unit ( The following is an example of registering units in the order of Gravity ).

). (grams)

( Specific

Step

Description

1. Press and hold (for about 2 seconds) the SAMPLE key in weighing mode.
of the function table is displayed.

Display and Key Operation

Press and hold (for about 2 seconds)

2. Press the SAMPLE key several times to display the

weighing unit

.

Press several times

3. Press the PRINT key to display

.

4. Press the RE-ZERO key to specify the unit and display the unit specification mark ” ” .

14

Step

Description

5. Press the SAMPLE several times to display

Display and Key Operation
.
Press several times

6. Press the RE-ZERO key to specify the unit and display the unit specification mark ” ” .

7. Press the PRINT key to register the specified unit.

8. Press the CAL key to return to weighing display.

9. Each time you press the MODE key, the units will switch in the specified order. Order from to . In the specific gravity mode, the unit is when calculating the density. The display unit is when measuring weight in air ( shows at the top left and the ” ” mark blinks) and when measuring weight in water ( shows at the top left, ” ” mark shows).
15

Selecting Substance ( Solid or Liquid )

Select a substance which is either solid or liquid. It can be specified at “substance selection

( )” of “density function (

)” in the function table.

Step

Description

Display and Key Operation

10. Press and hold (for about 2 seconds) the SAMPLE key while the scale is in weighing mode.
of the function table is displayed.

Press and hold (for about 2 seconds)

11. Press the SAMPLE key several times to display the

” density function (

) “.

Press several times

12. Press the PRINT key to enter the item.

16

Step

Description

13. Select substance using the following keys. SAMPLE key Used to select “substance selection ( )”.

Display and Key Operation

RE-ZERO key
Selects either “solid density measurement ( )” or “liquid density measurement ( )”.

14. Description of settings is as follows.

“Solid ( )”

Proceeds to “7.2. Measuring Solid Density (Specific Gravity),

Function Table

” after step 18.

“Liquid ( )”

Proceeds to “7.4. Measuring Liquid Density (Specific Gravity),

Function Table

” after step 18.

17

Selecting Input Method of Liquid Density Used for Solid Density Measurement (Specific Gravity)

When measuring the density (specific gravity) of a liquid (function table

input (

) ” setting is irrelevant, so proceed to step 17.

), the “liquid density

Step

Description

Display and Key Operation

15. The density of a liquid can be registered using the following keys.

SAMPLE key

Used to select the “liquid density input (

)”.

RE-ZERO key
Specifies either “Density input of liquid using water temperature ( )” or “Direct density input of liquid ( )”.

16. Description of settings is as follows.

“Water temperature input ( )”

Proceeds from step 7 of “7.2. Measuring Solid Density

(Specific Gravity), Function Table

” to “Method To

Input The Water Temperature (

)” of “7.3.

Specifying Liquid Density”.

“Direct density input ( ) ”

Proceeds from step 7 of “7.2. Measuring Solid Density

(Specific Gravity), Function Table

” to “Method To

Input The Density Directly (

)” of “7.3. Specifying

Liquid Density”.

18

Step

Description

17. Press the PRINT key to store the settings.

Display and Key Operation

18. All preparations are complete. Press the CAL key to enter the weighing mode to start measurement.

19. Press the MODE key to display the specific gravity mode

units.

Go to “7.2. Measuring Solid Density (Specific Gravity),

Function Table

” or “7.4. Measuring Liquid Density

(Specific Gravity), Function Table

“.

Measuring Solid

Density

(

)

or

Measuring Liquid

Density

(

)

Reference The density function (specific gravity) uses “density function (

)” of the function table.

Class

Item

Density function (Specific gravity)

Liquid density input
Substance selection

Parameter

Description

Density input of a liquid using water temperature

Direct density input of a liquid

Density measurement of a solid

Density measurement of a liquid

indicates factory settings. 19

7.2. Measuring Solid Density (Specific Gravity), Function Table
Cautions
When the temperature or type of liquid changes, register again the density of the liquid using “7.3. Specifying Liquid Density”. The measurement value of the density function (specific gravity mode) is fixed to 4 decimal places. The minimum division cannot be changed using the SAMPLE key. The procedure of the density (specific gravity) measurement is to weigh the sample in air, to weigh the sample in liquid and to display calculated density of the sample.

Procedure
Step

Description

Display and Key Operation

Weighing Operation

1. Weighing mode for in air

Preparation for measurement in air.

(

shows and blinks )

Press the RE-ZERO key to display zero with nothing is put on the upper pan and lower pan.

2. Put the sample on the upper pan and wait until the weighing value is stable. If necessary, press the PRINT key to output the weight of the sample.

Sample in the air

Example output: Weight in air A&D standard format (factory setting)

is a space

Weighing data output

3. Press the SAMPLE key to record weight in air and proceed to the weighing mode for liquid (
shows and shows ).

Cautions

The SAMPLE key is inactive when weighing value

is overload

.

20

Step

Description

4. Weighing mode for in liquid

To measure the density of the liquid, pour it into the beaker and sink the float.

(

shows, shows ).

Adjust the amount of the liquid so that the float is approximately 10 mm under the liquid surface when float is hung in the liquid.

liquid surface.
Approx. 10 mm Sample Lower pan

Display and Key Operation

Weighing Operation

Sample in the liquid

5. Press the PRINT key to output the weighing value.
Example output: Weight in air A&D standard format (factory setting)

is a space

6. Press the SAMPLE key to record the weight in the liquid and proceed to the liquid density input

mode (

shows and shows).

Weighing data output

Cautions

The SAMPLE key is inactive when weighing value

is overload

.

21

Step

Description

7. Liquid density input mode

Display and Key Operation

Input the density of the liquid.

Refer to “Method To Input The Water Temperature

(

)” (page 23) or “Method To Input The

Density Directly (

)” (page 24) in “7.3.

Specifying Liquid Density”.

Input the Water

Temperature

(

)

or

Weighing Operation
Sample in the liquid

Input the Density

Directly

(

)

8. Press the PRINT key to proceed to the density

display of a solid. (

shows and shows)

9. Solid density display mode
If necessary, while the density of the sample is displayed, press the PRINT key to output the density. The unit of density (specific gravity) is .
Example output: Density (specific gravity) A&D standard format (factory setting)

Weighing data output

is a space

10. If another sample is to be measured, press the SAMPLE key and proceed to step 1 of

“Weighing mode for in air” (

shows and

blinks ).

11. When the temperature or type of a liquid being measured changes, if necessary, register again the density of the liquid according to step 7 of “Liquid density input mode”.

12. If the MODE key is pressed, the display is changes to another weighing mode.
22

Refer to “Liquid density input mode” in
step 7.

7.3. Specifying Liquid Density

Select the density input method of a liquid when the solid density is measured.

The “liquid density input (

)” has “Method To Input The Water Temperature (

and “Method To Input The Density Directly (

)” (page 24).

)” (page

Method To Input The Water Temperature (

)

This step is an additional explanation of step 7 “Liquid density input mode” (page 22).

The current setting of water temperature is displayed. (Factory setting is 25.0 °C.)

Refer to Table1 in “5.2.1. Density of Water” regarding the relation between temperature and density of

water.

Register the water temperature using the following keys.

The setting range of temperature is 0.0 to 99.9 °C in 0.1 °C interval.

Step

Description

1. RE-ZERO key
Increases number of blinking digit. (+ key) (Number next 9 is 0.)

Display and Key Operation

MODE key
Decreases number of blinking digit. (- key) (Number next 0 is 9.)

SAMPLE key Moves blinking digit.

23

Step

Description

1. PRINT key
Stores the current setting and proceeds to the density display. (Go to Step 9. “Solid density display mode”) (page 22)

Display and Key Operation

CAL key
Cancels the setting and proceeds to the density display. (Go to Step 9. “Solid density display mode”) (page 22)

Method To Input The Density Directly (

)

This step is an additional explanation of step 7 “Liquid density input mode” (page 22).

The current setting of density of water is displayed. (Factory setting is 1.0000 g/cm3.)

Register density of water using the following keys.

The setting range of density is 0.0000 to 1.9999 g/cm3.

If the input becomes out of range, the balance displays

and returns to the input

display.

Step 1. RE-ZERO key

Description

Display and Key Operation

Increases number of blinking digit. (+ key) (Number next 9 is 0.)

24

Step

Description

1. MODE key
Decreases number of blinking digit. (- key) (Number next 0 is 9.)

SAMPLE key Moves blinking digit.

Display and Key Operation

PRINT key Stores the current setting and proceeds to the density display. (Go to Step 9. “Solid density display mode”) (page 22)
CAL key Cancels the setting and proceeds to the density display. (Go to Step 9. “Solid density display mode”) (page 22)

25

7.4. Measuring Liquid Density (Specific Gravity), Function Table
The measurement value of density (specific gravity) is fixed to 3 decimal places. Minimum division cannot be changed using the SAMPLE key. The procedure of the density (specific gravity) measurement is to weigh the float in air, to weigh the float in liquid and to display calculated density of the float. Each status and indications are as follows :

Procedure
Step

Description

Display and Key Operation

Weighing Operation

1. Weighing mode for in air

Preparation for a measurement in air.

(

shows ,

blinks )

Press the RE-ZERO key to display zero with nothing placed on the density pan stand.

2. Put the float on the upper pan and wait until the weighing value is stable. If necessary, press the PRINT key to output the weight of the sample..

Example output: Weight in air A&D standard format (factory setting)

is a space

Weighing data output

float in the air

3. Press the SAMPLE key to record weight in air and proceed to the weighing mode for liquid

(

shows and shows ).

Cautions

The SAMPLE key is inactive when weighing value

is overload

.

26

Step

Description

4. Weighing mode for in liquid

To measure the density of the liquid, pour it into the beaker and sink the float.

(

shows, shows ).

Adjust the amount of the liquid so that the float is approximately 10 mm under the liquid surface when float is hung in the liquid.

Liquid surface Approx. 10 mm Float

Display and Key Operation

Weighing Operation
float in liquid

5. Wait until the weighing value is stable. To output the weighing value, press the PRINT key.
Example output: Weight in liquid A&D standard format (factory setting)

is a space

6. Press the SAMPLE key to record the weight in the liquid and proceed to the float volume input

mode (

shows and

shows ).

Cautions

The SAMPLE key is inactive when weighing value

is overload

.

Weighing data output
volume input mode

7. Float volume input mode
Input the volume of the float. Refer to “7.5. Specifying Volume of Float” and input the volume of the float.

Refer to “7.5. Specifying Volume of Float”.

27

Step

Description

Display and Key Operation

8. Press the PRINT key to proceed to the density

display (

shows and shows ).

Weighing Operation

9. Liquid density display mode
If necessary, while the calculated density of the liquid is displayed, press the PRINT key to output the density. The unit of density (specific gravity) is .
Example output: density (specific gravity) A&D standard format (factory setting)

is a space

10. If another sample is to be measured, press the SAMPLE key and proceed to step 1 of
“Weighing mode for in air”

(

shows and

blinks ).

11. If the MODE key is pressed, the display is changes to another weighing mode.

float in liquid
Weighing data output

28

7.5. Specifying Volume of Float
This step is an additional explanation of step 7 “Float volume input mode” (page 27). The current volume of the float is displayed. (Factory setting is 10.00 cm3.) Register the volume using the following keys. The setting range of volume is 0.01 to 99.99 cm3 in 0.01 cm3 interval.

Step

Description

Display and Key Operation

1. RE-ZERO key

Increases number of a blinking digit. (+ key) (Number next 9 is 0.)

MODE key
Decreases number of a blinking digit. (- key) (Number next 0 is 9.)

SAMPLE key Moves a blinking digit.

PRINT key
Stores the current setting and proceeds to the density display. (Go to Step 9. “Liquid density display mode” ) ( Page 28.)

29

Step

Description

1. CAL key
Cancels the setting and proceeds to the density display. (Go to Step 9. “Liquid density display mode” ) ( Page 28.)

Display and Key Operation

30

8. Frequently Asked Questions and Answers
Question: I would like to measure the density of a resin pellet or sheet, which floats in water. Is this possible?
Answer: Use a liquid that has a lower density than water and does not dissolve the sample, such as methanol (density 0.798) or kerosene (density 0.80). The density of the liquid used is measured using the float provided with the kit.
Question: Can a sample containing bubbles be measured?
Answer: The density of a sample with bubbles contained can be measured as it is. But as time passes, the bubbles disappear and the apparent density may change. A sample, which floats on water due to this low density, cannot be measured.
Question: The measurement repeatability may be affected by the water’s surface tension. What can I do about this?
Answer: A few drops of a surfactant (for example, a mild detergent for washing dishes) added to the water reduces the influence of surface tension. A few drops of a surfactant will affect the liquid density only a very small amount. When methanol is used in place of water, the influence of surface tension is small, even without a surfactant.
Question: When tap water is used, bubbles are gradually generated on the sample surface and a measurement error occurs. What can I do about this?
Answer: Tap water contains dissolved gases such as oxygen and carbon dioxide. When tap water is used, the released dissolved gases generate bubbles. It is recommended that pure water or distilled water, which contains few dissolved gases, be used.
Question: I try to measure a highly water resistant material such as rubber, but bubbles stick to the sample. What can I do about this?
Answer: Before measurement, soak the sample in the water with an appropriate amount of surfactant added. Doing this increases the sample surface hydrophilicity and bubbles may only stick to the sample surface in a very small amount.
31

Question:

Up to what size of sample can be measured?

Answer:

Considering the density pan size, the maximum size of the sample that can be measured is as

follows: Diameter 25 mm

Height 30 mm

Question: Can I measure the density of a liquid with a high viscosity?
Answer: A liquid with a viscosity up to 500 [mPa x s] can be measured. If the viscosity exceeds this value, the float takes an excessive amount of time to sink and a measurement error occurs. Measuring adhesives is not recommended because the adhesive sample may be difficult to remove from the float.

Question: When a semi-micro balance is used, is accuracy improved?
Answer: Surface tension affects the measurement value in the range approximately between 0.2 mg and 1.0 mg. In a measurement using the 0.1 mg range, the magnitude of an error and the level of balance accuracy are almost the same. In a measurement using the 0.01 mg range, the magnitude of an error greatly exceeds the level of balance accuracy. Therefore using a semi-micro balance is not recommended.

32

MEMO
33

MEMO
34

A&D Company, Limited

3-23-14 Higashi-Ikebukuro, Toshima-ku, Tokyo 170-0013, JAPAN

Telephone: [81] (3) 5391-6132

Fax: [81] (3) 5391-1566

A&D ENGINEERING, INC.

47747 Warm Springs Blvd, Fremont, California 94539, U.S.A.

Tel: [1] 800-726-3364

Weighing Support:[1] 888-726-5931

Inspection Support:[1] 855-332-8815