This document describes the usage and characteristics of Extech Relative Humidity Calibration Standards. The calibration standards are made using Sodium Chloride (NaCl) and Magnesium Chloride (MgCl) to provide reference values of 75% and 33% relative humidity, respectively. The standards should be used at room temperature and provide relative humidity reference values at different temperatures.
The Extech RH300-CAL is a Relative Humidity Calibration Reference Standard designed for use with Extech RH300 Humidity Meters. The kit includes two bottles: one providing a 75% Relative Humidity reference using Sodium Chloride (NaCl) and another providing a 33% Relative Humidity reference using Magnesium Chloride (MgCl).
The document provides specific Relative Humidity reference values for both standards at various temperatures ranging from 50°F to 95°F. It also outlines care instructions, noting that the reference bottles must be kept tightly sealed when not in use and should be replaced immediately if the contents dry out or harden.
| 75% Reference Standard Composition | Sodium Chloride (NaCl) |
|---|---|
| 33% Reference Standard Composition | Magnesium Chloride (MgCl) |
| 75% RH at 68°F (20°C) | 75.47% |
| 33% RH at 68°F (20°C) | 33.07% |
The 75% reference uses Sodium Chloride (NaCl) and the 33% reference uses Magnesium Chloride (MgCl).
The Relative Humidity is 75.29% at 75°F (24°C).
The bottles must be immediately replaced.