How to Calibrate the Ohaus PX84/E Pioneer Analytical Balance

Accurate calibration is essential for maintaining the precision and reliability of analytical balances. The Ohaus PX84/E Pioneer Analytical Balance is designed for high-accuracy laboratory applications and requires external calibration using certified weights.

This guide explains how to properly calibrate the Ohaus PX84/E, following the calibration procedures outlined in the official Ohaus PX Series Instruction Manual, rewritten in a clear, practical, and SEO-optimized format. 

Understanding Calibration on the Ohaus PX84/E

The PX84/E is an ExCal (External Calibration) analytical balance, meaning:

• It does not contain an internal calibration weight

• Calibration must be performed using external certified calibration masses

• The balance supports:

  • Span Calibration

  • Linearity Calibration

According to the user manual, calibration is required:

• When the balance is installed for the first time

• After relocation

• When environmental conditions change

• As part of routine quality control or compliance programs

Pre-Calibration Checklist (Critical for Accuracy)

Before starting calibration, ensure all of the following conditions are met:

1. Warm-Up and Acclimatization

• Allow the PX84/E to warm up for at least 1.5 hours

• Analytical balances require longer stabilization for accurate results

2. Environmental Conditions

• Install the balance on a stable, vibration-free surface

• Avoid drafts, open windows, air conditioning, and direct sunlight

3. Level the Balance

• Adjust the leveling feet until the bubble indicator is centered

4. Use Correct Calibration Weights

For the Ohaus PX84/E, the official calibration values are:

• 50 g

• 80 g (full capacity)

Use ASTM Class 1 or equivalent certified calibration weights for analytical accuracy.

How to Perform Span Calibration on the PX84/E

Span calibration adjusts the balance using two reference points: zero load and a known calibration mass.

Step-by-Step Span Calibration Instructions

1. Power ON the balance

   • Ensure the weighing pan is empty

2. Access the Calibration Menu

   • Press and hold the Tare / Menu-Cal button

3. Select Span Calibration

   • Press Yes to enter the calibration menu

   • Press No until Span Cal appears

   • Press Yes to confirm

4. Apply the Calibration Weight

   • The display will show “Place weights”

   • Place the requested weight (typically 80 g) on the pan

   • To use a half-capacity point (50 g), press the Function / Mode button

5. Confirm Calibration

   • The balance captures the weight automatically

6. Remove the Weight

   • Follow the on-screen prompt to remove the calibration mass

7. Calibration Complete

   • The display will show “Calibration done”

   • Press any key to return to weighing mode

How to Perform Linearity Calibration(Recommended)

Linearity calibration improves accuracy across the entire weighing range, not just at a single point.

When Linearity Calibration Is Recommended

• For regulated laboratory environments

• If weighing results vary across different mass values

• After transportation or major temperature changes

Linearity Calibration Steps (Summary)

1. Enter the Calibration Menu

2. Select Linearity Cal

3. Follow the display prompts to apply:

   • Zero load

   • 50 g

   • 80 g

4. When complete, the display will show “Linearity done”

Calibration Best Practices for Analytical Balances

• Always calibrate with clean, temperature-stable weights

• Never touch weights with bare hands

• Perform calibration daily or weekly, depending on usage

• Keep calibration records for GLP, ISO, or GMP compliance

• Recalibrate after environmental changes

When to Use Professional Calibration Services

Professional calibration is recommended when:

• The balance is used under ISO, GLP, GMP, or USP regulations

• You require NIST-traceable calibration certificates

• The balance does not pass routine performance checks

Authorized service providers can verify accuracy and document compliance.

Final Thoughts

Proper calibration of the Ohaus PX84/E Pioneer Analytical Balance ensures consistent, accurate, and compliant weighing results. By following the official Ohaus procedures and maintaining proper environmental conditions, laboratories can rely on precise measurements and long-term balance performance.