# Lab Equipment Guide: Categories, Calibration and Safe Use

Source: https://www.verbalexperiment.com/blog/lab-equipment-guide
Published by Verbex. How these guides are written: https://www.verbalexperiment.com/how-we-write

You weigh the same salt twice and the balance disagrees by a few milligrams. The protocol is open, the water bath is already warm, and the service sticker on the side of the instrument is too faded to read. A lab equipment guide that only names what to buy will not tell you whether that reading is usable today.

Most wet-lab work rests on six jobs: measuring, holding temperature, separating mixtures, containing the sample, observing the result, and keeping people safe. The harder job is showing that the tool was fit for use on the day you used it. Checks, service history, and failures belong in the record next to the result.

By Multimod Labs

## Table of Contents

-   [Lab Equipment Categories at a Glance](#lab-equipment-categories-at-a-glance)
    -   [Lab equipment categories by function](#lab-equipment-categories-by-function)
    -   [How to mark your own bench](#how-to-mark-your-own-bench)
-   [Core Tools Every Wet Lab Starts With](#core-tools-every-wet-lab-starts-with)
-   [How to Choose Equipment That Fits Your Work](#how-to-choose-equipment-that-fits-your-work)
    -   [Six questions to write down first](#six-questions-to-write-down-first)
    -   [Repair, replace, or retire](#repair-replace-or-retire)
-   [Calibration Intervals for Common Instruments](#calibration-intervals-for-common-instruments)
    -   [Check and calibration frequency for common instruments](#check-and-calibration-frequency-for-common-instruments)
    -   [How to set the interval you will actually keep](#how-to-set-the-interval-you-will-actually-keep)
-   [How to Run a Pre-Use Check Safely](#how-to-run-a-pre-use-check-safely)
-   [Records That Show Equipment Was Fit for Use](#records-that-show-equipment-was-fit-for-use)
    -   [Equipment record fields and what each one preserves](#equipment-record-fields-and-what-each-one-preserves)
    -   [What belongs in the bench note](#what-belongs-in-the-bench-note)
-   [Build Your Equipment Register This Week](#build-your-equipment-register-this-week)

## Lab Equipment Categories at a Glance

Most wet-lab equipment falls into **six functional groups**: **measurement**, **heating and cooling**, **separation**, **containment**, **observation**, and **safety**. Grouping by what a tool must do is more useful than grouping by brand. You can look at today's experiment and ask which job is missing.

![A flowchart categorizing essential wet-lab equipment into six functional groups with descriptive labels and icons.](https://cdnimg.co/cab61d54-2a92-4be8-97b1-fd84150a185b/1bbb2ab8-453c-4c1a-bec1-c19e19fe565d/lab-equipment-guide-categories.jpg)

### Lab equipment categories by function

| Category | Typical equipment | Main function |
| --- | --- | --- |
| Measurement | Analytical balances, micropipettes, thermometers, pH meters | Quantify inputs and readings |
| Heating and cooling | Hot plates, water baths, incubators, refrigerators, freezers | Hold temperature for reactions and storage |
| Separation | Centrifuges, filtration units, chromatography systems | Split mixtures by density, size or affinity |
| Containment | Fume hoods, biosafety cabinets, glassware, chemical storage cabinets | Protect the user and the sample |
| Observation | Microscopes, spectrophotometers, plate readers | Read and record the result |
| Safety | Eyewash stations, safety showers, fire extinguishers, first-aid kits | Respond quickly when something goes wrong |

**Measurement** tools turn a mass, a volume, a temperature, or a pH into a number you can write down. **Heating and cooling** keeps a reaction or a stored sample at the temperature the method expects. **Separation** divides a mixture so the part you care about is no longer mixed with everything else. **Containment** holds the sample and keeps hazardous material away from the person at the bench. **Observation** is how you inspect or read the result after the steps are done. **Safety** gear is the response path when a splash, a fire, or an eye exposure happens.

### How to mark your own bench

Print the table or keep it on a clipboard. Circle any group where the bench has no working item. Then circle any group where one shared item carries almost all of the work, such as one centrifuge for the whole bay or one pH meter that everyone borrows.

A new researcher often treats the fume hood as furniture and the balance as the only serious instrument. Both are equipment. If the hood's airflow indicator is dark, containment has already failed, even when the balance looks fine. The same scan works for a teaching lab and for a small biotech bay. You are looking for a missing job, not a missing brand name.

> **Practical rule:** If you can't name the group a tool belongs to, you can't name the check that shows it worked.

## Core Tools Every Wet Lab Starts With

A new bench should not start with a centrifuge or a plate reader. It should start with the items that make ordinary solution work possible. For centuries, labs used one-off tools such as stone mortars, copper bowls, and glass vessels. By the middle of the nineteenth century, equipment was sold through trade catalogs and newspapers, so the same kind of item could be obtained and described in more than one place, as the [Lehigh University library exhibit on early laboratories](https://exhibits.lib.lehigh.edu/exhibits/show/lab/earlylabs) documents. Reproducible work needs tools you can name, obtain, and use the same way again.

![An educational infographic displaying seven essential wet lab bench tools, their primary functions, and common user mistakes.](https://cdnimg.co/cab61d54-2a92-4be8-97b1-fd84150a185b/52bb40d1-79bb-464d-a097-b67407ad1ce9/lab-equipment-guide-lab-tools.jpg)

Workbenches, storage cabinets, and a heat source were already a recognizable layout in the nineteenth century. Universities took up that layout then, and well-equipped school labs followed in the twentieth century. That history still matches a sensible buying order.

1.  **Analytical balance.** It weighs reagents and samples to the precision the method needs. The common slip is weighing into an open vessel that drifts in a draft or picks up moisture from the air.
2.  **Graduated pipettes and micropipettes.** They deliver a measured volume. The slip is a pipette nobody has checked, or a tip that doesn't seat on that model.
3.  **Beakers, flasks, and graduated cylinders.** They hold, mix, and measure solutions. Don't read a precise final volume from a beaker when the method calls for a volumetric flask.
4.  **Thermometer or temperature probe.** It confirms the bath, the room, or the storage unit. A thermometer that has never been compared with a reference is only a guess.
5.  **A stable bench.** It gives balances and readers a level surface with little vibration. A balance beside a door, a vent, or a shaking incubator will wander.
6.  **A heat source.** A hot plate or water bath warms under control. The dial setting is not the temperature. An independent probe is.
7.  **A storage cabinet.** It keeps chemicals and consumables apart by hazard class. Storing incompatible reagents in one cupboard is the mistake that looks tidy until it isn't.

Say a postdoc is setting up a shared bay for buffer prep. The balance, pipettes, glassware, probe, bench, bath, and cabinet come first. A centrifuge, a spectrophotometer, and an electrophoresis system come later, because they serve narrower analytical jobs. Clinics that also run diagnostic benches can look at [veterinary imaging and laboratory equipment](https://veterinarypracticeloans.com/veterinary-diagnostic-equipment/) when the same room has to support imaging and wet work, then still record which basic item was used for each run.

A short walk-through of a typical bench layout makes the buying order easier to picture before you spend on a specialized instrument.

Write the item into the experiment note. "Balance B2, 200 µL pipette P4, bath at the probe reading" is enough. The note is what lets someone else repeat the setup after you leave the bay.

## How to Choose Equipment That Fits Your Work

Purchase price is only one line in an instrument decision. Write six answers before you open a vendor brochure. The answers should describe your workflow, not the sales sheet.

A 2025 survey of more than 400 U.S. life-science laboratory professionals, reported by [Lab Manager](https://www.labmanager.com/the-data-backed-case-for-lab-visibility-33710), found that **nearly 60%** had significant unplanned downtime tied to equipment failures, missed calibration schedules, or difficulty locating critical assets. **More than 55%** ranked equipment-related expenses, including maintenance and calibration contracts, among their top three concerns. Those figures are why a cheap quote can become the expensive choice.

### Six questions to write down first

**Measured quantity and required accuracy.** How tight must the reading be for the conclusion it supports? A balance used for gravimetric standards is not the same decision as a balance used for rough media salts.

**Capacity and throughput.** Count the plates, tubes, or samples in a normal session, then add a failed run. Nominal speed on a data sheet is not the number of samples you finish before lunch.

**Footprint, power, ventilation, and noise.** The unit has to fit the bench, the circuit, and the exhaust it will use. A centrifuge that needs a dedicated outlet, or a hood that won't clear the ceiling, is not a fit.

**Service path.** Name who calibrates it, how fast a technician can arrive, and whether spare parts are stocked. A student lab with no metrology staff needs a named owner, or the knowledge leaves when that person graduates.

**Consumables and running costs.** Add tips, rotors, lamps, filters, service contracts, and replacement parts across the years you expect to keep the unit. The sticker price hides that total.

**Records the instrument produces.** A log, an export, or a printout that you can file with the result is part of the purchase. An instrument that only shows a number on a screen makes the later audit harder.

### Repair, replace, or retire

Buying the unit doesn't settle when to calibrate it, repair it, replace it, or take it out of service. Use downtime you have already had, how often it has been repaired, drift you have seen in routine checks, and the manufacturer's guidance. A cheaper unit with frequent unplanned stops and undocumented repairs can cost more across its life than a better-supported one, once contracts, consumables, and lost runs are counted.

> Write the criteria on one page before anyone compares models. The comparison then rests on your samples and your room, not on the brochure's highlighted line.

## Calibration Intervals for Common Instruments

**Calibration** assigns a value to an instrument by measuring it against a reference standard with a known value. That is the definition used by the [U.S. National Institute of Standards and Technology](https://nvlpubs.nist.gov/nistpubs/jres/106/1/j61cro.pdf). A reading that isn't tied to a reference is only a display.

NIST's account places statistical calibration designs in its laboratories in the late 1950s, when Joseph Cameron used experimental design and electronic computing. The same idea covered gauge-block length, sphere roundness, weight mass, angles, voltage from standard cells, and resistance with a one-ohm resistor. For a wet lab, the practical list is shorter. You still need the measured quantity, the reference, the acceptable error, the interval, the room conditions, and the record.

There is no single interval for every lab. Usage, how critical the measurement is, the manufacturer's guidance, and the instrument's past performance set it. A pipette used all day on a critical assay needs a tighter watch than a spare used once a month.

### Check and calibration frequency for common instruments

| Instrument | Check that confirms readings | Typical frequency |
| --- | --- | --- |
| Analytical balance | Check with certified reference weights | Before each critical weighing session; full interval set in the lab SOP |
| Micropipettes | Gravimetric or volume check | Periodic interval written in the lab SOP from use and risk |
| Thermometers and temperature probes | Comparison against a reference thermometer | Before use for critical work, then periodic per SOP |
| Freezers and refrigerators | Continuous temperature log and alarm test | Continuous logging; alarm test on the lab's periodic schedule |
| pH meter | Two-point buffer calibration | Before each session |
| Centrifuge | Speed check and rotor inspection | Interval printed in that model's manual |
| Spectrophotometer | Standard reference check at known wavelengths | Periodic interval written in the lab SOP for that model |

### How to set the interval you will actually keep

Start from the row, then tighten it with your own history. If a balance check weight has been inside limits for a year of daily use, the SOP interval can stay. If the same check has drifted twice in a month, shorten the interval and write the new date on the label. Don't guess a number the manual doesn't support, and don't copy another lab's calendar.

A balance check is a certified weight on the pan after the display settles, not a glance at yesterday's sticker. A pH meter gets two fresh buffers before the session, not one buffer from last week. A freezer log that nobody opens is not a check. The alarm test is the part that shows the log would have warned you.

Record the reference, the reading, the room conditions if the manual asks for them, and whether the result passed. That file is what separates an instrument fault from a real experimental result. A [calibration record](https://www.verbalexperiment.com/blog/calibration-record-software) kept next to the method makes the next due date visible before the run, not after a reviewer asks.

## How to Run a Pre-Use Check Safely

A pre-use check is a few minutes at the start of the session. It catches a dead cable, a missed due date, or a hood that isn't moving air before you commit a sample.

![A five-step infographic guide explaining how to perform a safety check on lab equipment before use.](https://cdnimg.co/cab61d54-2a92-4be8-97b1-fd84150a185b/35c122d3-35eb-4613-865f-ff689a504a5c/lab-equipment-guide-safety-check.jpg)

The short picture above is the scan. The written routine below is what you log.

1.  **Read the label or the log.** Confirm the last calibration or service date and the next due date. If the date has passed, don't start the run on the hope that it is "only a day over."
2.  **Look at the hardware.** Check for cracks, loose cables, leaks, a worn rotor, or a cracked sash pane. People skip this after the instrument "worked yesterday." Yesterday doesn't cover a rotor that was dropped at closing time.
3.  **Run the reference for that instrument.** Use a check weight, fresh buffers, or a reference thermometer, and write the number down. After a move, this step is the one people skip, and it is the step the move most affects.
4.  **Check the room.** Temperature, humidity, and vibration should sit inside the range the manual states. Weighing before the balance has settled in a draft is the classic slip.
5.  **Check containment and the emergency path.** The fume hood airflow indicator or the biosafety cabinet alarm should read normal, and the path to the eyewash should be clear. A box parked in front of the eyewash is a failed check.
6.  **Fail closed.** If any step fails, record the deviation and take the unit out of service. Don't "just finish this plate."
7.  **Note maintenance.** Log what you did and what is still planned, including a rotor inspection or a filter change that is due.
8.  **Shut down on purpose.** Return the unit to standby or power it down as the manual says, decontaminate the surfaces and parts you used, and log the end of use plus any deviation you noticed during the session.

[WHO microbiology-laboratory guidance](https://www.who.int/docs/default-source/medicines/norms-and-standards/guidelines/quality-control/trs961-annex2-goodpractices-pharmaceutical-microbiology-laboratories.pdf) calls for a documented program covering qualification, calibration, performance verification, maintenance, and monitoring of use. Essential equipment is maintained at predetermined intervals under a written procedure, with detailed records kept. Calibration and servicing dates, and the next due date, should show on the instrument label. The interval isn't a universal fixed number. It should reflect documented experience, the type of equipment, and its previous performance, and it should be shorter than the time the equipment has been shown to drift outside acceptable limits.

That is why the routine is written on the bench, not stored in someone's memory. A timer event, a failed check weight, and a hood alarm belong in the note while you are still standing there.

## Records That Show Equipment Was Fit for Use

A plate-reader result looks unusual three weeks later. To assess it, a colleague needs more than the displayed number: they need to identify the instrument, locate its records, and see what checks or repairs were documented around the time of use.

![A lab technician reviewing instrument records to verify equipment checks, emphasizing the importance of accurate documentation.](https://cdnimg.co/cab61d54-2a92-4be8-97b1-fd84150a185b/9ccf9649-97a9-4f7c-865b-5ddfa0678b65/lab-equipment-guide-instrument-records.jpg)

[WHO good-practice guidance for pharmaceutical quality-control laboratories](https://www.who.int/docs/default-source/medicines/norms-and-standards/guidelines/quality-control/trs957-annex1-goodpractices-harmaceuticalqualitycontrol-laboratories.pdf) describes equipment records as part of a planned system for calibration and maintenance. Measuring equipment should be calibrated according to a laboratory plan, and maintenance should be followed by a performance check. The record fields below connect a result to a specific device and its documented history.

### Equipment record fields and what each one preserves

| Record field | What it preserves |
| --- | --- |
| Equipment name, manufacturer and model | Identifies the instrument |
| Serial number or unique identifier | Links a result to one physical device |
| Location | Shows where the instrument was kept or used |
| Calibration dates and results | Shows what checks were recorded and when |
| Acceptance criteria | Defines what counts as a passing check |
| Next due date | Helps track when the next check is scheduled |
| Maintenance and repair history | Provides context for changes, drift or failures |
| Manufacturer instructions | Records the conditions and procedures specified for the instrument |

These details help explain a change in performance. If a balance was repaired on Tuesday, the repair belongs in its history. A post-repair check should also be recorded so the next user can see whether it passed before relying on the balance.

### What belongs in the bench note

Write down equipment events while they happen. A timer ending an incubation, a reference check outside its acceptance criteria, a freezer alarm, or a repair that changes how a balance settles may affect how someone interprets the experiment. A timestamped note preserves the context that memory can lose.

[Verbex: Voice Lab Notebook (iPhone and iPad app)](https://www.verbalexperiment.com) captures voice notes, typed notes, timers, and photos, organizes them into a structured record for review, and exports to PDF or Word for an existing ELN. It doesn't replace the lab's equipment register or a validated system. An [equipment maintenance log template](https://www.verbalexperiment.com/blog/equipment-maintenance-log-template) can help keep maintenance details alongside those bench records, with both pointing to the same device.

For electronic records under FDA rules, [21 CFR Part 11](https://ecfr.gov/current/title-21/part-11) requires closed systems to keep secure, computer-generated, time-stamped audit trails showing when operators create, modify, or delete records. Later edits must not hide what was recorded before, and the trail must be kept at least as long as the record. A bench note can support clear, contemporaneous documentation, but does not by itself guarantee compliance or replace a validated system.

## Build Your Equipment Register This Week

Start with the instruments that most affect your data. A spreadsheet is enough. Use these columns: instrument name, model, serial number, location, owner, last check, next due date, and open issues.

Fill five rows first.

-   **Analytical balance:** copy the model and serial from the label, not from memory.
-   **Micropipettes:** one row per pipette you use, with the last volume check.
-   **Main cold storage:** the freezer or refrigerator that holds the samples this project depends on.
-   **Centrifuge:** include rotor identity if the lab swaps rotors.
-   **Primary readout:** the spectrophotometer, plate reader, or microscope that produces the result you report.

Pull each cell from the instrument label, the service log, and the manufacturer's manual. If a check failed or drift isn't explained, mark the row as an open issue and point it at the bench note that recorded it. Durable stickers help when the factory label has worn off. You can [find printed labels online](https://theprintwarehouse.uk/printshop/sticker-and-labels) for asset IDs that match the serial column, then stick the same ID on the log.

The register is a scaffold for your own records. It isn't scientific, safety, or regulatory advice. Check every interval and every pass/fail limit against the manual and your local requirements. Verbex offers a free Lab Documentation Pack with **16 editable templates** as **42 Word, Excel, and PDF files**, with worked examples and working formulas. Those templates are documentation scaffolds, not scientific, safety, legal, or regulatory advice, and the examples need local review.

A [lab asset register](https://www.verbalexperiment.com/blog/lab-asset-management) only helps if someone opens it on time. Put one calendar reminder on the next due date of the most critical instrument, and write the name of the person who owns the register when a teammate leaves. A register nobody reviews only documents the failure after the run is already in doubt.

* * *

Verbal Experiment, or Verbex, is a private on-device lab documentation app for iPhone and iPad that captures voice notes, typed notes, timers, and images from the bench, then turns them into a source-backed record a scientist reviews before export. Completed records export as PDF, DOCX, or Markdown and can move into the ELN workflow you already use, including the equipment checks and deviations this guide asks you to write down. Visit [Verbal Experiment or Verbex](https://www.verbalexperiment.com) to see the app, which is free to download for iPhone and iPad.