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A Guide on How to Use a Balance including Troubleshooting Tips

How to Use a Laboratory Balance Correctly

A practical guide to accurate weighing, zeroing, taring, routine performance checks, weighing by difference and safe balance care.

A laboratory balance is used to determine the mass of samples, substances and equipment. Correct technique matters because errors in mass can affect concentration calculations, percentage yield, density, reaction quantities, repeatability and the validity of an investigation.

This guide explains how to select, set up and use a balance correctly; how zero and tare differ; how to carry out a simple routine check using a suitable test weight; how to control common sources of error; and how to clean, troubleshoot and care for weighing equipment safely.

Why Trust This Guide?

This guide was written and reviewed by Better Equipped's technical team, drawing on experience supplying laboratory balances, school balances, weighing accessories and practical science equipment to schools, colleges, universities and laboratories throughout the UK.

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Before You Start: Laboratory Balance Checklist

  • Select a balance with suitable capacity and readability for the task.
  • Place the balance on a firm, level surface away from the bench edge.
  • Keep it away from draughts, vibration, direct sunlight and rapidly changing temperatures.
  • Check that the weighing pan and surrounding area are clean, dry and free from residue.
  • Release any transport lock and assemble removable parts only as directed by the manufacturer.
  • Allow the balance to complete the manufacturer's specified warm-up period after switching on, reconnecting or moving it.
  • Check that the correct unit is selected and that the empty pan shows zero before use.
  • Use a clean weighing boat, weighing paper, beaker, watch glass or other compatible container when weighing substances.
  • Never place chemicals, biological material or liquids directly onto the weighing pan.
  • Make sure the sample, container and any pan accessories together will remain below the balance's maximum capacity.
  • Carry out any routine performance check required by the laboratory procedure before starting work.
  • Use the PPE and control measures identified by the activity's risk assessment.
  • Know the correct spill procedure before handling hazardous, dusty, corrosive or biological material.
Laboratory balance pre-use safety checklist

Parts of a Laboratory Balance and Their Functions

Labelled parts of a laboratory balance

Weighing Pan

The surface that supports the object or weighing container. Centre the load and make sure it does not touch the housing or draft shield.

Digital Display

Shows the balance indication and selected unit. Record the complete stable value shown; do not invent additional decimal places.

On / Off Button

Turns the balance on and off. Follow the manufacturer's warm-up and power-management instructions before accurate weighing.

Zero / Tare Control

Some balances use one key for both functions, but zero and tare are different. Zero establishes an empty-pan starting point; tare subtracts a load already on the pan.

Unit Button

Changes between enabled measurement units. Confirm the required unit before weighing and include it with every recorded result.

Levelling Feet

Adjustable feet used with the level indicator to position the balance correctly. Recheck the level after moving the balance.

Level Indicator

Often a bubble or electronic level that shows whether the balance is correctly positioned.

Draft Shield

An enclosure used on sensitive balances to reduce air movement. Close the doors before accepting a final reading.

Stability Indicator

A symbol or message showing that the balance regards the current indication as stable enough to read.

Calibration or Adjustment Control

Starts a model-specific internal or external procedure. Use it only in accordance with the manufacturer's instructions and laboratory policy.

Laboratory Balance Terminology Explained

Understanding the correct terms helps users choose appropriate equipment, follow methods accurately and interpret balance performance sensibly.

Term Meaning
Mass The quantity measured and reported by a laboratory balance, commonly in grams or kilograms.
Weight The force caused by gravity acting on a mass. Everyday language often uses “weight” for a weighing result, but laboratory balances normally report mass.
Indication The value shown by the balance display at a particular moment.
Zero The function used to establish the unloaded starting point when the weighing pan is empty.
Tare The function used to subtract the mass of a container or other load already on the pan so that the display can show the net sample mass.
Net Mass The mass of the sample alone after the tare load has been excluded from the displayed result.
Tare Mass The mass of the container or other item excluded from the displayed net result.
Gross Mass The total physical load: tare mass plus net sample mass.
Capacity The greatest total load permitted on the balance. The container, sample and accessories all count towards this limit, even after taring.
Readability The smallest mass increment displayed by the balance, such as 0.1 g, 0.01 g or 0.001 g.
Resolution A term used differently by manufacturers. It may refer to readability or to the number of display divisions across the weighing range, so the product specification should be checked.
Accuracy A general description of how close a measurement result is to an appropriate reference value. Readability alone does not prove accuracy.
Repeatability How closely repeated indications agree when the same load is measured under the same conditions.
Linearity How consistently the balance responds to different loads across its weighing range.
Eccentricity Variation caused by placing the same load at different positions on the weighing pan.
Calibration A comparison between balance indications and appropriate reference standards under specified conditions. Calibration identifies performance; it is not the same as changing the balance.
Adjustment An operation that changes the balance response so its indications correspond more closely to reference values. Adjustment should follow the manufacturer's or laboratory's authorised procedure.
Routine Performance Check A user check with a suitable test weight to confirm that the balance remains within the laboratory's defined acceptance limits.
Minimum Usable Sample Mass The smallest sample that can be weighed with performance suitable for the intended purpose. It depends on the balance, required tolerance and laboratory procedure—not just the displayed decimal places.
Analytical Balance A high-sensitivity balance, normally fitted with a draft shield and intended for small or demanding measurements.
Top Pan Balance A general-purpose balance widely used in schools and laboratories for routine weighing.
Weighing by Difference A transfer technique in which the mass delivered is calculated from the decrease in mass of the original container.
Remember: A balance that displays more decimal places is not automatically more accurate or more suitable. Choose equipment using the required sample size, capacity, tolerance and verified performance.

Common Types of Laboratory Balances

Different balances provide different combinations of capacity, readability, protection and robustness. The most sensitive available balance is not always the most suitable choice for a routine classroom task.

Top Pan Balance

A general-purpose digital balance used for routine school and laboratory weighing. It often provides a useful balance between capacity, readability and durability.

Precision Balance

Provides finer readability and stronger performance than a basic classroom balance for tasks where smaller mass differences matter.

Analytical Balance

Designed for highly sensitive measurements. It normally includes a draft shield and requires careful control of air movement, temperature, static, contamination and sample handling.

Triple Beam Balance

A mechanical teaching balance read by adding the positions of sliding poises. The digital zero, tare and unit-button procedures in this guide do not apply directly; follow the manufacturer's mechanical zeroing and reading instructions.

Choosing a balance? For help comparing capacity, readability, accuracy and balance types, read our balance buying guide.

Setting Up the Laboratory Balance

  1. Select a suitable location.
    Use a firm, stable bench away from open windows, fans, doors, vibrating equipment, direct sunlight and busy walkways.
  2. Prepare the balance correctly.
    Release any transport lock, fit the pan and accessories as instructed, and use only the approved power supply.
  3. Check that the balance is level.
    Use the level indicator and levelling feet where fitted. Recheck after the balance is moved.
  4. Switch on and allow warm-up.
    Follow the manufacturer's specified stabilisation time after switching on, reconnecting or changing location.
  5. Inspect and clean the weighing area.
    The pan, draft shield and surrounding surfaces must be clean, dry and correctly assembled.
  6. Select the required unit.
    For most school laboratory tasks this will be grams, but always follow the method.
  7. Establish empty-pan zero.
    With nothing on the pan, use the zero function if necessary and confirm that the display shows zero at the balance's normal readability.
  8. Complete any required routine check.
    Use the specified test weight and acceptance limit if the laboratory procedure requires a check before use.
  9. Select a suitable container.
    Use a clean, dry and compatible weighing boat, paper, beaker, watch glass or sample vessel.

Zero, Tare and Capacity: What Is the Difference?

Zero the Empty Pan

Use zero when the pan is empty to establish the unloaded starting point. Remove all containers and residue first.

Tare the Container

Place the empty container centrally on the pan, wait for stability and press tare. The display returns to zero while the container remains physically on the balance.

Respect Gross Capacity

Taring changes the displayed value but does not remove the load. The container, sample and accessories must remain below the maximum capacity.

Gross mass = tare mass + net sample mass
Capacity warning: If a 200 g container is tared on a 500 g balance, only the remaining permitted capacity is available for the sample and any other load. Never use tare to disguise an overload.
Zero, Tare and Capacity Explained

How to Tare a Balance

Taring allows the display to show the sample's net mass without including the container in the displayed result. The container still counts towards the physical load and maximum capacity.

  1. Check the empty-pan zero.
    Remove all items and confirm that the clean, empty pan shows zero in the selected unit.
  2. Place the empty container centrally on the pan.
    Make sure it is stable and does not touch the housing or draft shield.
  3. Wait for a stable indication.
    Close the draft-shield doors where fitted and wait for the stability symbol or a settled display.
  4. Press tare.
    The display should return to zero at the balance's normal readability while the container remains on the pan.
  5. Add the sample carefully.
    The display now shows the net mass of the sample.
Negative reading after taring: If the tared container is removed, the display may show a negative value approximately equal to its mass. This is normal. Replace the same container to continue, or clear the tare with the empty pan according to the balance instructions.

Routine Balance Check Using a Test Weight

A routine performance check is not the same as formal calibration. It is a practical check that the balance indication remains within a predefined limit before or during use. Follow the laboratory procedure and manufacturer guidance; not every school activity requires a documented check.

  1. Confirm the balance is ready.
    It should be warmed up, clean, correctly levelled, set to the required unit and showing empty-pan zero.
  2. Select the specified test weight.
    Use the weight, class and nominal value stated in the laboratory procedure. Do not substitute an unverified everyday object.
  3. Inspect and handle the weight correctly.
    Keep it clean and dry. Use suitable forceps, gloves or a weight-handling tool where required, and avoid touching precision weights with bare fingers.
  4. Allow temperature equilibration where needed.
    A cold or warm test weight can disturb sensitive measurements.
  5. Place the weight centrally on the pan.
    Do not slide it across the surface. Close the draft shield where fitted.
  6. Wait for the stability indication.
    Record the complete displayed value and unit if documentation is required.
  7. Compare with the acceptance limit.
    Use the tolerance defined by the laboratory, not the readability alone.
  8. Respond correctly to failure.
    Do not adjust the balance merely to make the result pass unless authorised. Label or remove it from use and report it according to local procedure.
  9. Remove and store the weight safely.
    Return it to its protective case or designated storage location.
Important distinction: A successful routine check supports confidence that the balance is functioning within the defined limit. It does not replace appropriate calibration, maintenance or repair.
Routine Check Using a Test Weight

How to Weigh a Sample

How to set up a balance and weigh a sample
  1. Confirm that the balance is ready.
    Check the location, level, warm-up, unit, cleanliness and empty-pan zero.
  2. Choose a suitable weighing container.
    It should be clean, dry, stable and compatible with the sample.
  3. Place the empty container centrally on the pan.
    Make sure it does not touch the draft shield, balance body or nearby objects.
  4. Wait for stability and press tare.
    The display should return to zero while the container remains in place.
  5. Add the sample carefully.
    Use a clean spatula, pipette or suitable transfer tool. Add small amounts when approaching a target mass and avoid spilling onto the balance.
  6. Close the draft shield where fitted.
    Open only the door needed for transfer and close all doors before accepting the result.
  7. Wait for the stability indicator.
    Do not record an indication that is still changing.
  8. Record the complete result.
    Write the displayed value, unit and all shown decimal places. Include the balance identity, temperature or other details where required by the method.
  9. Remove the sample safely.
    Do not drag containers across the pan and do not return excess reagent to the stock container unless the laboratory procedure explicitly permits it.
  10. Inspect and clean the area.
    Deal with residue or spills using the substance-specific and manufacturer-approved procedure.
Important: Never place chemicals directly onto the balance pan. Do not weigh a leaking container, an unstable load or a sample that could exceed the total permitted capacity.

Weighing Liquids and Difficult Samples

Some materials change mass, disturb air movement or interact with the balance during the measurement. The method and risk assessment should determine the correct container and handling technique.

Sample or Condition Possible Effect Good Practice
Liquid Spillage, sloshing, evaporation or liquid on the outside of the container may alter the result or damage the balance. Use a stable, compatible and dry container. Keep the outside clean and dry, use a lid or stopper where appropriate, and provide secondary containment if required.
Warm or Cold Sample Temperature differences can create convection currents and unstable or biased indications. Where the method permits, allow the sample and container to approach the balance's ambient temperature before weighing.
Hygroscopic Sample The sample can absorb moisture and gain mass while exposed to air. Minimise exposure, keep the source container closed and use a covered receiving vessel where suitable.
Volatile Sample Evaporation can cause a steadily decreasing indication. Use a covered or stoppered compatible container and work promptly according to the method and risk assessment.
Static-Prone Powder or Plastic Electrostatic forces can cause drifting, erratic or biased indications. Avoid rubbing plastic containers, use suitable antistatic controls where authorised and consider a less static-prone container.
Fine or Hazardous Powder Dust may escape, expose users, contaminate the balance or enter the mechanism. Use appropriate containment and extraction, minimise open handling and follow the substance-specific control procedure. Do not dry-brush or blow escaped hazardous powder.
Large or Awkward Object Off-centre loading or contact with the balance housing can distort the result. Use a balance with a suitable pan and capacity. Centre the load and ensure it is fully supported without touching surrounding surfaces.
Magnetic Sample Magnetic interaction with balance components may affect the indication. Follow the manufacturer's guidance and use an approved non-magnetic support or separation method if required.
Small samples: A balance may display a small mass without being sufficiently reliable for the intended purpose. Select the balance using the required tolerance and minimum sample size, not the number of decimal places alone.

Weighing by Difference

Weighing by difference determines the amount transferred from the decrease in mass of the original source container. It is useful when powder may remain in the source vessel or when complete transfer to the receiving vessel cannot be assumed.

Step Example What It Tells You
Weigh the closed or prepared source container before transfer Container + sample = 12.64 g The starting mass before any sample is transferred.
Transfer sample to the receiving vessel Some solid is poured or tapped out The exact amount delivered does not have to be judged by appearance.
Reweigh the same source container after transfer Container + remaining sample = 10.21 g The mass remaining after transfer.
Calculate the difference 12.64 g − 10.21 g = 2.43 g 2.43 g of sample was transferred.
Mass transferred = mass before transfer − mass after transfer
  • Use the same balance for both measurements.
  • Use the same source container, closure and external condition for both measurements.
  • Close or cover the source container before each reading where appropriate.
  • Do not clean, refill or otherwise alter the source container between the two readings.
  • Avoid losing material from the outside of the source container.
  • Record both values at the balance's displayed readability.
  • For volatile or hygroscopic samples, minimise the time between measurements.
Weighing by Difference

Improving Weighing Quality

Laboratory balance accuracy tips

Reliable weighing depends on the balance, the environment, the sample and the user's technique. The table below explains common effects and suitable controls.

Factor Possible Effect How to Reduce the Problem
Draughts Fluctuating or biased indications, especially on sensitive balances. Keep away from open windows, doors, fans and busy walkways. Close the draft shield before recording.
Vibration The indication may not stabilise or may vary when nearby equipment operates. Use a firm bench and keep the balance away from centrifuges, pumps, moving equipment and repeated impact.
Temperature difference Warm or cold samples can create air currents and measurement drift. Allow thermal equilibration where the method permits and do not place hot vessels directly on the pan.
Static electricity Erratic, slowly changing or unexpectedly biased indications. Avoid rubbing plastic, use suitable containers and apply authorised antistatic controls where necessary.
Evaporation or moisture uptake A steadily decreasing or increasing indication. Use compatible covers or closures, minimise exposure and work promptly.
Dirty pan or container Added mass, contamination and poor repeatability. Use clean, dry equipment and inspect the balance before and after use.
Incorrect levelling Systematic error or reduced performance. Check the level indicator and adjust the feet after moving or repositioning the balance.
Off-centre loading The result may depend on the position of the load on the pan. Place containers and objects centrally and avoid overhanging loads.
Contact with the housing The load is not fully supported by the weighing mechanism, producing an incorrect result. Make sure the container does not touch the draft shield, balance body, cables or nearby objects.
Wrong unit Recording and calculation errors. Check the selected unit before weighing and include it with every result.
Overloading Unreliable results and possible permanent damage. Check total gross load, including the tared container and accessories, before weighing.
Unsuitable balance The balance may lack adequate capacity, readability or verified performance for the task. Match the equipment to the largest load, smallest sample and permitted measurement tolerance.
Repeatability tip: For a comparative investigation, use the same suitable balance, container type and weighing technique throughout where possible. Record any balance change that could affect comparability.
Sources of Weighing Error

Common School, GCSE and Laboratory Uses for Balances

Balances support quantitative preparation, fair testing and calculations across chemistry, biology and physics. The selected balance must be appropriate for the mass range and uncertainty tolerated by the activity.

Activity Typical Equipment Skills Practised
Preparing standard solutions Suitable balance, weighing container, spatula, beaker, wash bottle and volumetric flask Accurate mass measurement, quantitative transfer and concentration calculations.
Measuring solid reactants Balance, spatula, weighing boat or paper and reaction vessel Container selection, taring, controlled addition and recording units.
Conservation of mass experiments Balance and a suitable closed reaction system Comparing total mass before and after a reaction while preventing loss of matter.
Food calorimetry Balance, food sample, calorimeter and thermometer Measuring sample mass or mass change and using the result in energy calculations.
Rates of reaction by mass loss Balance, reaction vessel, reagents, timer and suitable containment Recording mass at timed intervals and controlling experimental variables.
Density practicals Balance, measuring cylinder, ruler or displacement equipment Combining mass and volume measurements to calculate density.

Equipment Commonly Used With Laboratory Balances

Suitable accessories protect the balance, reduce contamination and make transfer more controlled. Every container and accessory placed on the pan contributes to the gross load.

Weighing Boats

Lightweight containers for many powders, granules and small samples. Check chemical compatibility and static behaviour before use.

View Weighing Boats

Weighing Paper

Useful for suitable dry, non-reactive substances and for controlled transfer of small quantities.

View Weighing Paper

Spatulas

Used to add or transfer small quantities of solid material. Use a clean tool appropriate to the substance.

View Spatulas

Beakers and Containers

Suitable for larger, liquid or contained samples when stable, dry and chemically compatible.

View Beakers

Calibration Weights

Appropriate reference weights may be used for authorised calibration, adjustment or routine checks. Select, handle and store them according to the applicable procedure.

View Weights

Forceps

Useful for handling small objects, suitable test weights and components while reducing contamination from fingers.

View Forceps

Watch Glasses

Can provide a stable container for suitable small samples where their shape and chemical resistance are appropriate.

View Watch Glasses

Laboratory Balances

Choose from school balances, top pan balances and other weighing equipment for practical science.

View Balances
Accessory tip: Choose the lightest suitable container that safely controls the sample. A heavy container reduces the remaining capacity available after taring.

Cleaning and Laboratory Balance Care

Laboratory balance cleaning and care guide
  • Remove all samples, containers and weighing paper after use.
  • Identify the spilled or deposited material before choosing a cleaning method.
  • For a small amount of known, non-hazardous dry residue, follow the manufacturer's instructions; a clean soft brush may be suitable on some models.
  • Do not brush, blow or use compressed air on hazardous, unknown, sensitising or fine dusty material.
  • Follow the substance-specific spill procedure, SDS and local guidance for hazardous or unknown contamination.
  • Use only cleaning agents and tools compatible with the balance materials and approved by the manufacturer.
  • Apply cleaning liquid to a cloth or wipe where appropriate; do not pour or spray liquid directly onto the balance.
  • Keep the display, buttons, vents, sockets and power connection dry.
  • Remove the pan or draft-shield components only where the manufacturer permits it, and refit them correctly.
  • Never immerse the balance housing or scrape the pan with sharp metal tools.
  • Allow all parts to dry fully before reassembly and reuse.
  • Recheck the level and complete any required performance check after moving, dismantling or major cleaning.
  • Switch off or leave powered according to the manufacturer's instructions and laboratory procedure.
  • Use the recommended cover or close the draft shield when the balance is not in use.
  • Report damage, corrosion, contamination, unstable readings or faults to a technician or supervisor.
Hazardous residue: Do not treat all powder as ordinary dust. Isolate the balance and obtain the correct spill instructions before attempting to clean hazardous or unidentified material.

Common Laboratory Balance Mistakes and How to Avoid Them

Mistake Why It Matters How to Avoid It
Using tare instead of establishing empty-pan zero The user may conceal residue or an existing load rather than starting from a genuinely empty pan. Remove all items, inspect the pan and establish zero first; tare only after placing the empty container.
Not taring the container The displayed result includes both container and sample. Place the empty container centrally, wait for stability and press tare before adding the sample.
Ignoring the tared container when checking capacity The balance may be overloaded even though the display shows only the net sample mass. Check the total gross load: container, sample and all accessories.
Putting chemicals directly on the pan This can contaminate or damage the balance and expose later users. Use a clean, dry and compatible weighing container.
Recording before stability The indication may still be changing. Close the draft shield where fitted and wait for the stability indicator.
Placing the load off-centre The result may be affected by eccentric loading. Place the container or object centrally on the pan.
Allowing a container to touch the housing Part of the load may be supported outside the weighing mechanism. Ensure free clearance from the draft shield, body, cables and surrounding bench.
Weighing a hot or cold object Convection and temperature effects may cause drift. Allow temperature equilibration where the method permits.
Choosing by decimal places alone Readability does not by itself establish accuracy or suitability for a small sample. Consider capacity, smallest sample, required tolerance and verified performance.
Returning excess reagent to stock The stock container may be contaminated. Follow the local procedure for excess material and chemical waste.
Dry-brushing unknown or hazardous powder Dust may be dispersed into the air or mechanism. Stop, isolate the area and use the substance-specific spill procedure.
Leaving residue on the pan Later readings may be affected and other samples contaminated. Inspect and clean the balance using the correct method after use.

Laboratory Balance Troubleshooting Guide

Problem Possible Cause What to Do
Balance will not turn on Power supply disconnected, batteries depleted, transport damage or equipment fault. Check the approved power supply, batteries and socket. Do not dismantle the balance; report the fault if it remains unresponsive.
Indication keeps changing randomly Draughts, vibration, static, unstable support, sample movement or contact with the housing. Close the draft shield, remove sources of vibration, centre the load and check that nothing touches the container.
Indication rises slowly Moisture uptake, temperature equilibration or environmental drift. Consider whether the sample is hygroscopic or at a different temperature and use the appropriate covered-container method.
Indication falls slowly Evaporation, cooling or sample loss. Check for volatility, leaks and temperature effects; use a compatible covered or stoppered container where appropriate.
Display does not show zero with an empty pan Residue, an object on the pan, incomplete warm-up, zero drift or equipment fault. Remove all loads, clean and inspect the pan, check warm-up and use the zero function. Report persistent drift.
Mass appears incorrect Wrong unit, container not tared, balance not level, off-centre load, failed check or inappropriate balance. Review the complete setup and repeat the measurement. Remove the balance from use if it fails the defined routine check.
Result changes with pan position Eccentricity problem, damaged pan support or unsuitable large load. Centre the load. Report significant position-dependent results and do not rely on the balance until assessed.
Overload warning appears The total physical load exceeds the permitted capacity. Remove the load immediately. Remember that a tared container still counts towards capacity, and use a more suitable balance.
Negative value appears after removing the container The container had been tared. This is normal. Replace the same container or clear the tare with the empty pan according to the balance instructions.
Sample spills on the balance Material added too quickly, unstable container or unsuitable handling method. Stop work, identify the material and follow the correct spill procedure. Do not resume use until the balance is clean, dry and safe.
Buttons are not responding Power issue, keypad lock, contamination, liquid ingress or equipment fault. Do not force the controls. Isolate the balance if necessary and report the fault.
Routine check fails Incorrect setup, unsuitable or contaminated weight, environmental problem, adjustment drift or equipment fault. Check the setup and test weight once according to the procedure. Do not repeatedly adjust or retest to obtain a pass; report and label the balance as required.

Common Laboratory Incidents Involving a Balance

Balance emergency actions for spills faults and broken glass

Chemical or Biological Spill

Stop work, warn others and restrict access. Identify the material and follow the relevant spill procedure, SDS, risk assessment and local guidance. Do not brush or blow hazardous powder.

Electrical Fault or Liquid Ingress

Do not touch wet electrical parts. Isolate the supply only if this can be done safely, keep the balance out of use and report the incident.

Broken Glass

Keep people away and do not collect fragments with bare hands. Use the approved broken-glass procedure and check the balance for damage or contamination before reuse.

Overload or Impact

Remove the load safely, stop using the balance and report the incident. A balance may require inspection and a performance check even if it still switches on.

Do not resume use: A contaminated, wet, overloaded or damaged balance should remain out of service until it has been made safe, correctly reassembled and checked according to local procedure.

Laboratory Balance FAQs

What is the tare function on a balance?

Tare subtracts the mass of a container or other load already on the pan so that the display can show the net mass added afterwards. The tared load still counts towards the balance's maximum capacity.

What is the difference between zero and tare?

Zero establishes the unloaded starting point with an empty pan. Tare excludes the displayed mass of a container or load already on the pan. Some balances use the same physical button for both functions, but the purposes are different.

What is the difference between mass and weight?

Mass is the quantity reported by a laboratory balance, commonly in grams. Weight is the force caused by gravity acting on a mass. Everyday language often calls a weighing result “weight”, but laboratory records normally report mass.

Why will my balance not stabilise?

Possible causes include draughts, vibration, static electricity, a warm or cold sample, evaporation, moisture uptake, sample movement, off-centre loading or contact between the container and balance housing.

Can I place chemicals directly on a balance pan?

No. Use a clean, dry and compatible weighing container or weighing paper to protect the balance and control contamination.

How many decimal places should I record?

Record the complete stable value shown by the balance, including the unit and all displayed decimal places. Do not add digits that the balance does not display.

Does a balance showing more decimal places give a more accurate result?

Not necessarily. Displayed readability is only one characteristic. Suitability also depends on repeatability, calibration status, environmental conditions, sample size, capacity and the tolerance required by the method.

What is the difference between a top pan balance and an analytical balance?

A top pan balance is generally intended for routine weighing. An analytical balance is more sensitive, normally includes a draft shield and requires stricter control of the environment and technique.

How often should a laboratory balance be calibrated or checked?

There is no universal interval. Follow the manufacturer's guidance, laboratory quality system and risk-based procedure. Checks may also be needed after movement, repair, adjustment, impact, overload or unexplained performance change.

Is a routine test-weight check the same as calibration?

No. A routine check confirms performance against a defined acceptance limit. Calibration is a formal comparison with reference standards under specified conditions, and adjustment is the separate act of changing the balance response.

Why does my balance show a negative number?

This commonly occurs when a tared container is removed. Replace the same container to continue or clear the tare with the empty pan according to the balance instructions.

What balance should schools use?

Many routine school practicals use robust top pan balances. The correct choice depends on the largest total load, smallest sample, required tolerance, environment and teaching objective.

Can I weigh a hot container?

Hot containers may damage the balance and create convection currents that disturb the result. Unless the method and manufacturer explicitly allow otherwise, let the container cool safely towards ambient temperature before weighing.

What should I do if I add too much chemical?

Do not return excess material to the original stock container unless the laboratory procedure specifically permits it. Follow the local procedure for using, transferring or disposing of the excess.

Need Help Choosing a Laboratory Balance?

Now that you understand how to use a balance correctly, the next step is choosing equipment that matches the required gross capacity, readability, smallest sample, practical activity and acceptable measurement tolerance.

Our balance range includes school balances, laboratory balances and weighing equipment suitable for science classrooms, prep rooms, colleges and laboratories.

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About This Guide

This guide was written and reviewed by Better Equipped's technical team, drawing on experience supplying laboratory balances, school balances, weighing accessories and practical science equipment to schools, colleges, universities and laboratories throughout the UK.

It is intended as general educational guidance for routine laboratory weighing. It does not replace the balance manufacturer's instructions, an activity-specific risk assessment, chemical safety information, formal metrology procedures or the laboratory's quality system.

Our aim is to help users weigh samples accurately, prevent equipment damage, improve practical science technique and choose suitable weighing equipment for their setting. If you have any questions about balances, weighing accessories or school science equipment, our technical team would be pleased to help.

Last reviewed and updated: August 2026

Always follow your laboratory's procedures, the activity risk assessment and the balance manufacturer's instructions.