トビ温泉
Tobi OnsenSampled at wellhead
黄
Sulfur
Classification
Calcium-Magnesium-Sodium Sulfate-Bicarbonate spring
Tobi Onsen is a naturally welling hot spring (63.5 °C) in the Tsurumi district of Beppu, classified as a simple sulfur spring of the hydrogen-sulfide subtype. The water is weakly acidic at pH around 5.3 — colorless and clear at the wellhead but carrying an unmistakable strong rotten-egg note of H₂S, with 45.7 mg/kg of free hydrogen sulfide and 221.8 mg/kg of free CO₂. Total dissolved solids are light at 148 mg/kg, so the body of the water is gentle while the sulfur aroma defines the bathing experience.
pH
5.30
Weakly acidic
Source temperature
63.5°C
Hot
Tonicity
0.15g/kg
Hypotonic
Free CO₂
222mg/kg
Low
Free H₂S
46mg/kg
Very high
Radon
6.40Bq/kg
Low
- Color
- colorless and transparent
- Taste
- tasteless
- Odor
- strong hydrogen sulfide
Highlights
- Sulfur-rich
- Top-decile hot
Analyzed Nov 5, 2019·株式会社 東洋環境分析センター·Cert no. yZ1904615-001