The pH Buffer Powder Calibration Kit (3-Pack) provides a complete set of precision reference standards for calibrating digital pH pens, laboratory glass probes, and continuous water quality monitors. The kit includes three pre-measured powder sachets covering the full testing spectrum: pH 4.01 (acidic), pH 6.86 (neutral), and pH 9.18 (alkaline) at 25°C. Dissolving each packet into distilled water produces exactly 250ml of standard reference buffer solution, enabling full three-point calibration for maximum measurement linearity and accuracy.

Specifications

• Kit Contents: 3 sachets (pH 4.01, pH 6.86, and pH 9.18 buffer powders)
• Standard Calibration Temperature: 25°C
• Solution Yield: 250ml of standard buffer solution per packet (750ml total yield)
• Accuracy: ±0.01 pH at 25°C
• Sachet Dimensions: 60mm x 70mm x 3mm
• Net Weight: ~6g per packet
• Shelf Life (Sealed Powder): Up to 2 years (stored in a cool, dry place away from direct sunlight)
• Compatibility: Universal standard for all digital pH pens, benchtop laboratory meters, and industrial electrodes

Key Features

• Full 3-Point Calibration Capability: Covers acidic (4.01), neutral (6.86), and alkaline (9.18) points to accurately align both probe zero-offset and full-span electrode slope.
• Pre-Measured Accuracy: Eliminates the need for analytical laboratory balances—each sealed sachet dissolves cleanly into exactly 250ml of pure water.
• Extended Shelf Life: Dry powder formulation prevents degradation and atmospheric CO2 absorption, outlasting standard bottled liquid buffers.
• High Chemical Stability: Delivers repeatable, temperature-charted reference curves with ±0.01 pH precision.

Common Applications

• Hydroponics & Aquaponics: Routine calibration of nutrient reservoir monitors, dosers, and handheld testing pens.
• Aquariums & Aquaculture: Precise monitoring for planted freshwater tanks, brackish setups, and high-pH marine reef tanks.
• Water Treatment & RO Plants: Verifying drinking water purifiers, reverse osmosis systems, swimming pools, and industrial effluent neutralizing systems.
• Laboratories & Brewing: Food testing, craft beer mash tracking, soil pH sampling, and school chemistry education.

Preparation and Mixing Guide

1. Prepare three clean containers (beakers, volumetric flasks, or clean glass jars) with a capacity greater than 250ml. Label them clearly: pH 4.01, pH 6.86, and pH 9.18.
2. Pour the complete contents of each respective packet into its labelled container.
3. Add exactly 250ml of distilled or deionized water to each container. Do not use tap water, bottled drinking water, or mineral water.
4. Stir each solution thoroughly using a clean glass rod until the powder completely dissolves.
5. The calibration reference solutions are ready for immediate use.

Calibration Best Practices

• Calibration Sequence: Always begin with the neutral solution (pH 6.86) to establish the electrode zero-offset. Follow with the acidic standard (pH 4.01) or alkaline standard (pH 9.18) depending on your expected testing range, or calibrate all three for full-range linearity.
• Rinse Between Solutions: Thoroughly rinse the pH probe tip with distilled water and gently blot it dry with a lint-free tissue between containers to prevent cross-contamination.
• Liquid Storage: Store prepared liquid solutions in airtight, tightly sealed glass or HDPE bottles in a cool, dark place (or refrigerator). Discard mixed solutions after 3 to 4 weeks, or immediately if discoloration or sediment appears.
• Temperature Compensation: Buffer pH shifts slightly with temperature. If your meter lacks Automatic Temperature Compensation (ATC), ensure the calibration solution temperature is as close to 25°C (77°F) as possible during adjustment.