===== Vaisala HMK15 Humidity Calibrator =====

  * Description: Calibration set up for Vaisala Humidity Sensors
  * Manufacturer: [[https://www.vaisala.com/en|Vaisala]]
  * Manufacturer Spec Site: [[https://www.vaisala.com/en/products/instruments-sensors-and-other-measurement-devices/instruments-industrial-measurements/hmk15|Vaisala HMK15 Humidity Calibrator]]
  * Model: HMK15
  * Manual: [[file:///C:/Users/vosas/Downloads/HMK15-User-Guide-M210185EN-E.pdf|HMK15 User Guide]]

==== Parts ====
{{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_142944.png?400|}}
{{:undefined:screenshot_2026-06-30_144243.png?400|}}
  * Main Board
    * Salt Solution Chambers (x2)
    * Sensor Cap Attachment (x2)
    * Sensor Cap Plugs (x10)
    * Thermometer
  * Measuring Cup
    * {{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_140049.png?200|}}
  * Plastic Probe/Stirring Stick
    * {{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_140059.png?200|}}
  * Adapter Rings (x3)
    * {{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_143016.png?300|}}{{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_143025.png?300|}}
  * Salts
    * {{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_135932.png?300|}}{{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_143008.png?300|}}
    * NaCl (75% RH)
    * K2SO4 (97% RH)
  * Calibration/Preparation Date Tags
    * {{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_140023.png?300|}}
  * Certificate of Calibration/Inspection
    * {{:atmos:citation:instruments:vaisalahmk15calibrator:screenshot_2026-06-30_140036.png?300|}}


==== Calibration Process ====

Need:
  * HMK15 Humidity Calibrator
  * Vaisala Humidity Sensor
  * Deionized water

Steps:
  - Prepare salt solutions
    - 
    - Depending on the frequency of use and the general operating conditions, the salt solutions maintain their characteristics for 6 - 12 months, after which they must be replaced. Perform a visual check every 2 - 3 months. There must be a minimum of 10 % of undissolved salt at the bottom of the chamber (max. 90 %). The salt must be clean, otherwise it must be reprepared.
  - Wait 24 hours
  - Calibrate Instrument
    -