The Elcometer 116 & Bacharach 116C Whirling Sling Hygrometers are designed to determine the dewpoint and relative humidity at any given time using the classic wet and dry bulb principle (psychrometric method).

The Elcometer 116A Whirling Hygrometer (typically the rotating/whirling style) is available in Celsius scale only. It comes with a supplied guide/table for quick Relative Humidity (RH) determination from the wet and dry bulb readings, and the dewpoint can be precisely calculated using the separate Elcometer 114 Dewpoint Calculator for added accuracy.

The Elcometer 116C Sling Hygrometer (the black self-contained unit often shown in photos) is a convenient, all-in-one instrument featuring an inbuilt slide rule for direct on-device calculation of %RH and dewpoint—no external charts or calculators needed. It uses reliable spirit-filled thermometers and is available in both °C and °F scales.

Key features and benefits include:

• Manual operation — No batteries, power supply, or electronics required, making it ideal for remote sites, hazardous environments (e.g., explosive atmospheres), or anywhere reliability without power is essential.
• Spirit-filled thermometers — Durable, mercury-free, and accurate for field use.
• Measuring range: -5°C to 50°C (23°F to 122°F) for both wet and dry bulb temperatures.
• Typical RH accuracy: ±5% RH (based on standard psychrometric tables and proper technique).
• Lightweight and compact design for easy portability and handling.
• Compliant with relevant standards such as ASTM E337-B, BS 2842, and ISO 8502-4 — commonly used in surface preparation, coating inspection, painting, and climatic condition monitoring before applying protective coatings.

These traditional sling/whirling psychrometers remain a trusted, cost-effective choice in industries like industrial finishing, marine, construction, and quality control where digital alternatives might fail or be impractical. For best results, ensure the wick is kept clean/wet with distilled water and whirl/sling vigorously for 1–2 minutes before reading.

• Elcometer 116 Whirling Hygrometer or Elcometer 116 Sling Hygrometer
• Slide rule table
• Operating instructions

Elcometer 116 & Bacharach 116C Whirling Sling Hygrometers Data Sheet