4 Major Ways to Make Lab Weighing Easier
Analytical and precision balances are highly sensitive, which can make it challenging to weigh effectively in any laboratory. By paying attention to four factors – the environment, the balance itself, how you handle your samples and your general operating procedures - and adjusting according to your needs, you can make lab weighing much easier.
1. Manage Your Weighing Environment
While you might consider your laboratory a stable, reliable ecosystem, perfect for performing feats of science, your balance may not agree! Environmental influences that we learn to ignore can wreak havoc on your weighing results. If you notice your results drifting, jumping or taking longer to stabilise for seemingly no reason, consider whether your environment may be a factor, and how you can fix it.
Temperature
When it comes to semi-micro balances, sudden temperature shifts can cause inconsistent readings. Two things can happen. One, the metals and plastics in the balance expand and contract at different rates, influencing how the mechs work together. Two, convection currents within the draft shield could develop, raising the weighing pan and putting pressure against samples.
Attempt to keep your balance at a consistent temperature throughout the day, away from beams of light, warm machinery, vents and drafty windows. If you must move the balance to a different location, ensure you’re leaving enough time for the balance to get used to a new temperature before calibration and use. We recommend at least 12 hours, so that the balance properly acclimatises to the environment.
Air & Wind
Many semi-micro, analytical and precision balances come pre-fit with a draft shield, since even mild breezes can add force to your samples that make them register as heavier than they really are. Before recording your lab weighing results, ensure the draft shield is completely closed – left, right and on top. Plus, with breezes typically comes cooler temperatures, which ties hand-in-hand with our previous section.
Vibrations
Vibrations are an ever-present nuisance in busy laboratory buildings. The only way to avoid them is to be exceptionally grounded – which is what accessories like Adam’s AVT Anti Vibration Table helps with. The same force that pushes a coffee cup won't move a boulder – so vibrations don’t move the heavy granite block your balance sits on. Suddenly, footsteps won’t make your lab weighing results jump!
Static & Humidity
Nobody likes static shocks, which is why your balance operates best when the humidity in the lab is over 40%. When it’s 40% or under, you’re more likely to generate static electricity. Static can develop with friction between samples, sample containers (plastic and vinyl especially) and the weighing pan, from nitrile gloves or your clothing, etc. You might see your lab weighing results drifting or samples beginning to lift or stick where they aren’t supposed to.
To make your life easier, invest in an ioniser like Adam’s ABI-1. All you have to do is turn it on and point it toward your balance. It will neutralise static electricity so it never messes with your results again.
2. Pay Attention to Your Lab Balance!
If you don’t treat your balance right, your balance won’t treat you right! Here’s what you must pay special attention to when you’re using your balance:
Using the Right Lab Balance
Your job will be exponentially better if you’re using the right tool for it. Not all balances are created equal, so ensure the one you’re using has everything you need. Pay attention to:
Capacity
Can your balance hold the weight of everything it needs to, containers included, with room to spare? If not, consider looking for a balance with a higher capacity.
Readability
Consider getting a lab balance that's one decimal finer than you need. For example, if you need 0.001g results, get a balance with a readability of 0.0001g. This will help you ensure that your 0.001g records are spot-on. Avoid going beyond one decimal finer, however, since you could be dealing with higher balance sensitivity when it’s not necessary.
Applications
Do you perform tasks that require weight related calculations outside of basic lab weighing? Some balances offer more additional applications than others, like percentage weighing, dynamic weighing or checkweighing. Having the balance do all the work removes the effort of calculating yourself and lowers the risk of errors.
These are only a few of the considerations that could impact which scale is right for you. Inscale offers a variety of laboratory balances that could make a great fit for your lab.
Calibrating Properly
Whether you’re performing internal or external calibration, follow the proper procedures to get the best result.
Both types of calibration require the same first five steps:
- Clear the weighing pan of all items
- Zero the display
- Close the draft shield completely
- Ensure the balance is level
- Press the calibration button on your balance
With internal calibration, the process ends there, all you have to do is wait for calibration to complete automatically. It can even be scheduled for when you’re not there!
External requires a few more steps, and thus someone needs to be present to perform the calibration:
6. When prompted by the display, place the calibration weight directly on the pan, without dragging it (which could create static)
7. Close the draft shield completely
8. Proceed with the process, typically by pressing a button to confirm
9. When prompted by the display, remove the calibration weight by lifting it directly from the pan, without dragging
Then, your balance will be accurate and precise once more!
Cleaning Regularly
A dirty balance doesn’t always look like a dirty balance at first glance. However, dust, spilt powder, liquid residue and finger oils can add up quickly. Try to keep up with cleaning to ensure that none of this becomes an issue later.
To clean a lab balance, you’ll want to use methods that don’t add to the mess. For example, using a paper towel can leave paper particles behind. We recommend a microfibre towel instead, especially for liquid spills. Your fingers could leave streaks and oils, so when attempting to clean solid debris, a soft bristled brush may work best to sweep it away.
When a thorough cleaning is required, such as if a sample has spilled and has left a residue, you could always use an ethanol-based cleanser. Ethanol evaporates quickly and doesn’t leave behind a residue itself.
Ensure the Balance is Level
Levelling bubbles are extremely helpful tools, which is why many laboratory balances have them built in. By adjusting the front and back feet, you can ensure that the bubble is dead-centre, which assists with getting accurate results. When your balance isn’t level, your samples are tilted, putting more weight on some of the pan, rather than distributing it evenly.
3. Handle Samples Effectively
Sample prep is extremely important and can be the difference between an accurate result and an inaccurate result.
Room Temperature Samples
Whenever you can, attempt to weigh samples that are the same temperature as the balance, which is (ideally) room temperature. Weighing a sample significantly hotter or colder than the balance can create convection currents in the draft shield, as we mentioned earlier. Place the sample near the balance and allow the two to equalise. When this is done, the only potential issue you would have to handle is when the balance itself heats up during use. Luckily, Adam’s new Polaris Semi-Micro Balance offers Air Diversion Technology to divert the hot air from the internal mechs away from the weighing pan.
Sometimes, the only option is to weigh a warm or cold sample – especially if they’ll change in any significant way when they’re room temperature. Unfortunately, if you’re weighing a hot or cold object and you’re using a lab balance with a draft shield, you won’t be able to avoid creating convection currents. Ensure you’re building in a margin of error and attempt to keep the weighing session short – waiting especially long if switching between hot and cold samples.
Powders Without Static
Powder samples can develop static, and you’re none the wiser until your results are wonky. It’s hard to prevent staticky powders, as the particles are creating friction between themselves at all times. A great option is to use an ioniser, like the ABI-1, and place the sample in front of it to neutralise any static that generates.
4. Pay Close Attention to Your Weighing Technique
As we now understand, your balance is only one part of the equation – and you’re not getting off scot-free. The way you and your colleagues interact with your balance, samples and calibration weights have an impact on your accuracy. Proper training is crucial, don’t ignore it!
Tare with Care
Tare is an excellent function that allows you to see your weighing results without the additional weight of any containers you’re using. However, because the containers become an “invisible” weight, it can be easy to forget that they’re still being taken into account. For example, if you start using a different kind of container, you need to ensure you’re re-taring that weight, even if it’s only for one sample. Similarly, make it a habit to Zero the results on your scale before you conclude weighing for the day, even if it’s already set to zero. This will help prevent tared weights being forgotten and left to ruin your day the next time you weigh.
Always Use Protection
When using laboratory balances, it’s considered a best practice not to touch anything with your bare hands. This is because the oil and sweat on your fingers can spread, and not only can it add a minute amount of weight to your results over time, but it can also begin to eat away at extremely precise tools like calibration weights. Gloves or tweezers, always!
Close Your Draft Shields
It can be a little tedious to open and close the draft shield on a lab balance every single time you want to place or remove a sample. However, as we’ve learned earlier in the blog, the doors really do need to be completely closed every time to prevent wind gusts from effecting results.
Wait for Results to Stabilise
Don’t just record the first result that comes on the screen! Laboratory balances are notorious for taking a bit longer than other scales to completely stabilise, because they’re so sensitive. Always wait for the little symbol that looks like this “ ~ “ to pop up, which indicates the results aren’t going to change again.
If the results take longer than usual to settle, it could be one of the many reasons listed above.
Slow Down
There’s no need to be a speed demon in the laboratory. Take your time and ensure you’re doing everything properly. Are the draft shields closed? Containers tared properly? Results recorded only after stabilised? Calibrated recently? Got gloves on? Balance clean?
It’s a lot to look after, but it’s all worth it to be one hundred percent sure that your results are valid and trustworthy.
Consider Printing Results
This one is really a personal preference, but we recommend using a printer like Adam’s ATP 2 to transcribe your results, rather than writing them down yourself. Your balance will transcribe exactly what’s on the screen, which makes it more reliable than a human, who could write a number incorrectly, round to the wrong decimal place or simply have unreadable handwriting.
An alternative to a printer, which is still a hardcopy, is to have your results fed directly into software like AdamDU. AdamDU takes all of your results and performs real-time analysis, saving you effort later.
Track Your Technicians
No one wants to play the blame-game, but it can be very helpful to narrow any lab weighing errors down to who was operating and when. Adam lab balances allow you to set individual operator profiles, each with their own password. You can even see who received a specific result when printing. Keeping track of technicians in this way makes it easier to identify holes in training, so you can address them before real harm is done!
Manuals Exist for a Reason
At Inscale, each product listing comes with the manual linked front and center. If every balance were the same, that wouldn’t be necessary, but since every machine has a different operating system, it’s important to keep the manual nearby. You’ll be walked through all the specs, the different functions the balance can perform, tips and tricks and everything in between. Read your manual!
Ultimately – lab weighing is difficult. No one can deny that! But with Inscale’s range of lab balances and accessories, you’re in the best shape for accurate results every time.
Have questions? Contact the Inscale team, we’re here to help.
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