Buyer's Guide
Analytical & Weighing Equipment
A complete procurement guide for laboratory measurement and analytical instruments — balances, water purifiers, spectrophotometers, fluorometers, desiccators, and microplate readers.
Understanding Analytical & Weighing Equipment
Analytical and weighing equipment provides the measurement foundation for every quantitative laboratory. From the balances that weigh your reagents to the spectrophotometers that measure your sample concentrations and the water purifiers that supply reagent-grade water, these instruments directly impact the accuracy and reproducibility of your results.
This guide covers six categories of analytical instruments. For each, we explain the technology, key specifications, and common applications to help you select the right measurement tools for your laboratory.
Legacy Lab Supplies is an authorized distributor for Yamato Scientific, Benchmark Scientific, and other leading manufacturers. All analytical equipment carries full manufacturer warranty with our competitive pricing.
Laboratory Balances
Laboratory balances range from ultra-microbalances reading to 0.0001 mg to high-capacity precision balances weighing up to 64 kg. Analytical balances (0.1 mg readability) are the workhorses of quantitative chemistry, while precision balances serve formulation, routine weighing, and industrial applications. Features include internal calibration, draft shields, GLP/GMP data output, and connectivity.
Readability
0.0001 mg to 0.1 g
Capacity
1 g to 64+ kg
Calibration
Internal motorized or external weights
Connectivity
RS-232, USB, Bluetooth, Wi-Fi
Common Applications
- Gravimetric analysis
- Standards & reagent preparation
- Quality control weighing
- Formulation & compounding
Water Purification Systems (General & Support Equipment)
Laboratory water purifiers produce Type I (ultrapure), Type II (general lab grade), or Type III (RO) water from tap water sources. Systems use combinations of reverse osmosis, deionization, UV oxidation, and ultrafiltration to achieve the required purity. Proper water quality is critical for reproducible results in analytical chemistry, molecular biology, and cell culture.
Purity Grades
Type I (18.2 MΩ·cm), Type II, Type III
Flow Rate
0.5 to 15+ L/min
TOC
<5 ppb (Type I)
Technologies
RO, DI, UV, UF
Common Applications
- HPLC & mass spectrometry
- Cell culture media
- Buffer & reagent preparation
- Glassware rinsing
Desiccators (General & Support Equipment)
Desiccators provide a dry, controlled environment for storing hygroscopic samples, cooling heated samples to room temperature, and protecting moisture-sensitive materials. Available as standard (passive desiccant) or vacuum desiccators for enhanced moisture removal. Automatic desiccators maintain precise humidity levels with electronic controls.
Type
Standard, vacuum, or automatic
Humidity
<25% RH (standard), <5% RH (vacuum)
Material
Polycarbonate, acrylic, glass, or stainless
Capacity
3L to 100L+
Common Applications
- Gravimetric analysis cooling
- Hygroscopic sample storage
- Electronics & optics storage
- Moisture-sensitive reagent protection
Spectrophotometers
Spectrophotometers measure the absorption or transmission of light through liquid samples at specific wavelengths. UV-Vis models cover 190-1100 nm for nucleic acid quantification, protein assays, enzyme kinetics, and chemical analysis. Nano-volume (micro-volume) spectrophotometers require only 1-2 µL of sample, eliminating the need for dilution.
Wavelength Range
190-1100 nm (UV-Vis)
Sample Volume
1 µL (nano) to 3+ mL (cuvette)
Bandwidth
1 nm to 5 nm
Light Source
Xenon flash, deuterium/tungsten
Common Applications
- Nucleic acid quantification (A260/A280)
- Protein concentration (Bradford, BCA)
- Enzyme kinetics
- Water quality analysis
Fluorometers
Fluorometers measure the fluorescent emission of samples excited at specific wavelengths, providing much higher sensitivity than absorbance-based methods. They are ideal for quantifying low-abundance nucleic acids and proteins using fluorescent dyes. Benchtop models offer walk-up simplicity, while microplate fluorometers provide high-throughput capability.
Excitation
LED or lamp-based, selectable wavelengths
Sensitivity
pg/µL range for nucleic acids
Sample Volume
1-20 µL (tube-based)
Assay Kits
dsDNA, ssDNA, RNA, protein
Common Applications
- Low-concentration DNA/RNA quantification
- Protein quantification
- Pre-sequencing QC
- Environmental sample analysis
Microplate Readers (Life Science)
Microplate readers detect and quantify reactions in 96-well to 384-well plates using absorbance, fluorescence, luminescence, or combinations thereof. Multimode readers offer flexibility for diverse assay types. Single-mode readers provide cost-effective solutions for dedicated applications like ELISA or reporter gene assays.
Detection Modes
Absorbance, fluorescence, luminescence
Plate Formats
6-well to 384-well
Read Speed
96-well in <10 seconds (absorbance)
Software
Curve fitting, kinetics, endpoint
Common Applications
- ELISA & immunoassays
- Cell viability assays
- Reporter gene assays
- Enzyme kinetics
How to Choose: Analytical Equipment Comparison
Compare the four primary analytical instrument categories.
| Factor | Balance | Spectrophotometer | Fluorometer | Water Purifier |
|---|---|---|---|---|
| Measures | Mass | Light absorption | Fluorescence | Water purity |
| Sensitivity | 0.0001 mg | ng/µL range | pg/µL range | 18.2 MΩ·cm |
| Key Application | Quantitative weighing | Concentration assays | Low-abundance QC | Reagent preparation |
| Price Range | $500-$10,000+ | $2,000-$30,000 | $3,000-$15,000 | $3,000-$25,000+ |
| Maintenance | Annual calibration | Lamp replacement | LED (low maintenance) | Filter & cartridge changes |
Key Specifications Checklist
Verify these factors before purchasing analytical equipment:
Frequently Asked Questions
What is the difference between an analytical balance and a precision balance?
Analytical balances read to 0.0001 g (0.1 mg) and are used for gravimetric analysis, standards preparation, and applications requiring high accuracy. Precision balances read to 0.001 g (1 mg) or 0.01 g (10 mg) and handle routine weighing, formulation, and general laboratory use. Analytical balances require draft shields and vibration-free surfaces; precision balances are more tolerant of environmental conditions.
What water purity grade do I need for my laboratory?
Type I (ultrapure, 18.2 MΩ·cm) water is required for HPLC, mass spectrometry, cell culture, and molecular biology. Type II (general laboratory grade) is suitable for buffer preparation, media preparation, and general chemistry. Type III (reverse osmosis) is used for glassware rinsing, water baths, and autoclaves. Most labs need at least Type II, with Type I for sensitive analytical work.
When should I use a spectrophotometer versus a fluorometer?
Spectrophotometers measure light absorption and are standard for concentration measurements (Beer-Lambert law), enzyme kinetics, and nucleic acid quantification at 260/280 nm. Fluorometers measure fluorescent emission and offer much higher sensitivity — up to 1,000x more sensitive than absorbance. Use a fluorometer when quantifying very low concentrations or when using fluorescent probes and dyes.
How often do laboratory balances need calibration?
For regulated environments (GLP, GMP, ISO 17025), balances should be calibrated at least annually by an accredited service, with daily or weekly internal calibration checks using certified reference weights. For general research use, annual professional calibration plus routine internal checks are standard. Many modern balances include motorized internal calibration for convenient daily verification.
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