Ohaus Density Determination User Manual

Density Determination Kit

Instruction Manual

天平密度测定组件

天平密度测定组件

天平密度测定组件天平密度测定组件

使用说明书

使用说明书

使用说明书使用说明书

（（（（适用于

适用于 EX/

适用于适用于

EX/EP/

EP/VP/

EX/EX/

EP/EP/

VP/CAV/

CAV/AV/

VP/VP/

CAV/CAV/

AV/AR/PA

AR/PA/CP

AV/AV/

AR/PAAR/PA

/CP 系列电子天平

系列电子天平））））

/CP/CP

系列电子天平系列电子天平

This Kit is compatible with OHAUS® Adventurer™, Adventurer™ Pro (except AV53x),
Adventurer™ SL (except AS153x), Pioneer, Explorer
models with capacities up to 610g and readability of 0.1mg and 1mg, Explorer
capacities up to 1100g and readability of 0.1mg and 1mg. Before using this accessory,
carefully read these instructions.

®

Pro, Voyager® and Voyager® Pro

®

models with

Table of Contents 目目目目 录录录录

1 Introduction................................................................................................................EN-1

1.1

Before we begin....................................................................................................................EN-1

1.2

2 Preparing the balance for density determinations..................................................EN-3

3 Principle of the density determination.....................................................................EN-3

4 Density determination of solids ...............................................................................EN-4

4.1

4.2

4.3

5 Density determination of liquids ..............................................................................EN-6

5.1

5.2

5.3

6 Supplementary information ......................................................................................EN-8

6.1

6.2

6.3

奥豪斯天平密度测定组件操作使用说明书

奥豪斯天平密度测定组件操作使用说明书 ................................

奥豪斯天平密度测定组件操作使用说明书奥豪斯天平密度测定组件操作使用说明书

Standard equipment..............................................................................................................EN-1

Fundamentals .......................................................................................................................EN-4

Performing the density determination of solids ....................................................................EN-4

Improving the accuracy of the result ....................................................................................EN-6

Fundamentals .................................................................................................................................. EN-6

Performing the density determination of liquids ................................................................... EN-7

Improving the accuracy of the result ....................................................................................EN-8

Influencing factors.................................................................................................................EN-8

Density table for distilled water...........................................................................................EN-10

Density table for ethanol.....................................................................................................EN-11

.........................................

................................................................

......... CN

..................

CN----1111

CNCN

1111

标准部件

标准部件 ................................

标准部件标准部件

2222 密度测定前

密度测定前天平的准备

密度测定前密度测定前

3333 密度测定的原理

密度测定的原理 ................................

密度测定的原理密度测定的原理

3.1 固体密度测定 ................................................................... CN-4

3.2 液体密度的测定 ................................................................. CN-6

4444 附录

附录 ................................

附录附录

4.1 密度测定的影响因素 ............................................................. CN-7

4.2 附表 1 蒸馏水密度表 ............................................................ CN-8

4.3 附表 2 乙醇密度表 .............................................................. CN-9

................................................................

................................................................

天平的准备 ................................

天平的准备天平的准备

...........................................................

................................................................

................................................................

................................................................

.....................................................

................................................................

....................................CN

................................................................

..................... CN

..........................................

........................... CN

......................................................

.....................................

................................................................

..... CN

..........

CN----2222

CNCN

CN----4444

CNCN

CN----4444

CNCN

CN----7777

CNCN

EN-1 Density Determination Kit

2

4

6 7 8

1 Introduction

1.1 Before we begin

Thanks for purchasing the density determination kit for your OHAUS balances. With the aid of this kit you can
use your balance for the determination of the density of solids and liquids.

1.2 Standard equipment

The kit contains the individual parts shown in the illustration below.

For the density determination of liquids, you need the kit and also the optional 10ml sinker.

1 Glass beaker 2 Bracket

3 Forceps 4 Platforms

5 Holder for floating solids 6 Holder for non floating solids

7 Precision thermometer with holder 8 Sinker 10ml (optional equipment)

1

3

5

Density Determination Kit EN-2

9 Pan support (Height = 38.1mm)

For AR 0.1mg/EP/VP

10 Pan support (Height = 23.5mm)

For PA 0.1mg/CP 0.1mg

11 Pan support (Diameter = 22.8mm)

For PA1mg/CP1mg/AR1mg/EX 1mg

12 Pan support (Diameter = 19.8mm)

For AV/CAV

13 Pan support (Diameter = 18.6mm)

For EX 0.1mg

14 Off setting weights A

15 Off setting weights B

Balances Weights NO.

EX 1mg A 1

AV 1mg A 1

EP/VP 1mg

PA/CP 1mg

A 3

B 1

Quantity

EN-3 Density Determination Kit

2 Preparing the balance for density determinations

This section describes how you can convert your balance to determine
densities. Please follow the steps as below.

Select the pan support according to your balance as described in Section 1.2.
Remove the cover of tape on the pan support, and adhere centrally to the
bottom of the bracket (2).

1. Open the draft shield door and remove the weighing pan.

2. Place the bracket with the pan support on the weighing cone.

3. Place the platform (4) above the bracket. The three support feet should be
between the weighing arms of bracket and stand stably on the bottom
plate of draft shield.

Note: The bracket must not touch the platform under any

circumstances!

3 Principle of the density determination

The density ρ is the quotient of the mass m and the volume V.

The international system of units specifies Kg/m
to lab purposes.

Density determinations are frequently performed by Archimedes’ principle, which is also used with the density
determination kit for the balances. This principle states that every solid body immersed in a fluid apparently
loses weight by an amount equal to that of the fluid it displaces.

The procedure for the density determination by Archimedes’ principle depends on whether the density of

solids or liquids has to be determined.

3

as the unit of density. However, the unit g/cm3 is better suited

Density Determination Kit EN-4

4 Density determination of solids

4.1 Fundamentals

The density of a solid is determined with the aid of a liquid whose density ρ0 is known (water or ethanol are
usually used as auxiliary liquids). The solid is weighed in air (A) and then in the auxiliary liquid (B). The density ρ
can be calculated from the two weighings as follows:

ρ = Density of sample

A = Weight of sample in air

B = Weight of sample in the auxiliary liquid

ρ

= Density of the auxiliary liquid

0

= Air density (0.0012 g/cm3)

ρ

L

α = Balance correction factor (0.99985), takes air
buoyancy of the adjustment weight into account.

4.2 Performing the density determination of solids

Note: These instructions explain how to work with the density

determination kit. They describe the procedure for performing a density
determination manually.

If you need information about operating your balance, please refer to the
instruction manual provided with the balance.

For the density determination of solids, use the glass beaker (2) and one of
the two holders for solids which float (5) or sink (6). For certain OHAUS
1mg balances, use off setting weights according to your balance as
described in Section 1.2.

Prepare the balance for the density determination (install platform and
bracket) as described in Section 2.

Suspend the supplied thermometer (7) from the edge of the beaker (1).
Place the beaker on the platform and fill it with auxiliary liquid (liquid of
known density ρ

ensure the solid is covered by at least 1 cm liquid after immersion.

Suspend the suitable holder (5) or (6) for solids which float or sink from the
bracket (the adjacent illustration shows the holder for solid which sink).

Ensure that no air bubbles adhere to the immersed part of the holder
(Remove any air bubbles by moving the holder or by means of a fine
brush).

usually distilled water or ethanol). Add enough liquid to

0’

For certain OHAUS 1mg balances, place off setting weights on the holder
(the adjacent illustration shows the weights for EP/VP 1mg balances).

Close the draft shield doors and tare the balance.

EN-5 Density Determination Kit

Place the solid in one of the two weighing pans of the bracket (2). Wait until
the weight display of the balance is stable and note the displayed weight A
(weight of sample in air).

Note for 0.1mg models

When solids with a weight greater than 20g are weighed in air, place in
the pan at the top of the holder (above 20g corner load errors may appear
on one arm in the weighing).

Remove the solid from the pan, close the draft shield doors and tare the
balance.

Place the solid after in the holder (6). Ensure that no air bubbles adhere to
the solid (remove any air bubbles with a fine brush).

Note

3

With solids with a density less than 1g/cm

the holder for floating

solids (5) must be used as it holds the solid body below the surface of the

auxiliary liquid. If the buoyancy of the solid is greater than the weight of
the holder, the holder must be weighted by placing an additional weight on
the top weighing pan of the bracket. After loading the additional weight,

tare the balance and restart the density determination procedure by
first weighing the solid in air (A) and then in the auxiliary liquid (B).

Wait until the balance has reached stability and note the displayed weight
B (weight of sample in the auxiliary liquid).

Now determine the density ρ of the solid according to the preceding
formula (Section 4.1).