Calibration - HMK15

HMK15 User Guide

Document code
M210185EN
Revision
D
Language
English (United States)
Product
HMK15
Document type
User guide

Leave the HMK15 calibrator and the probe at the calibration site for at least 30 minutes before starting the calibration in order to let the probe temperature stabilize to room temperature.

With lithium chloride, it is not necessary to use the thermometer, as the humidity reading changes only very slightly in temperature range +25 ... +30 °C (+77 ... 86 °F). However, if you use the thermometer, make sure that the sleeve is in the correct position and insert it into the 13.5 mm (0.53 in) hole of the LiCl salt chamber.

See also HMK15 chamber cover options.

Handle the thermometer as little as possible and do not touch the measuring end. Press the thermometer downwards until it passes the O-rings. The thermometer is correctly in place when you feel a resistance while pressing it downwards.
  1. Remove the grid or filter protecting the sensor. Take care not to damage the sensor.
    When calibrating HPP271 or HPP272 probes, or when using cover 253277SP with any 12 mm diameter probe, leave the grid or filter on.
  2. Some 12 mm (0.47 in) probes need an adapter fitting if used in the 13.5 mm (0.53 in) hole of the HMK15 standard chamber cover. The adapter fitting prevents the sensor from soaking in the salt liquid.

    In case you need an adapter fitting, remove the grid or filter and replace it with the adapter fitting. Two adapter fittings are provided on the base plate of the HMK15.

    CAUTION

    Remember to check your device's user guide if the adapter fitting is needed.

    If the sensor accidently soaks in salt liquid, remove it quickly and rinse with clean water. Let it dry before taking into use again.

  3. Insert the probe into a suitable hole of the LiCl salt chamber. Press it downwards until it passes the O-rings. The shorter the time the hole stays open before inserting the probe, the shorter the stabilization time required.
  4. Wait until the humidity reading stabilizes; this takes about 10 … 30 minutes.
  5. Read the salt chamber temperature from the thermometer and then read the closest humidity value from the calibration table (Greenspan's Calibration, LiCl solution).
  6. Adjust the dry end (DRY, offset) to correspond to the value given in the calibration table.
  7. Insert the thermometer into the 13.5 mm (0.53 in) hole of the NaCl salt chamber.
    When calibrating probes that are being used for long term measurements (over 1 hour) in high humidities (90 … 100 %RH), use the K2SO4 salt as the high end reference.
  8. Insert the probe into a suitable hole of the NaCl (or K2SO4) salt chamber. The shorter the time the hole stays open before inserting the probe, the shorter the stabilization time required.
  9. Wait until the humidity reading stabilizes; this takes about 10 … 30 minutes. Note that in high humidities the risk for errors increases. Therefore, the stabilization time should be longer (approximately 20 … 40 minutes).
  10. Read the salt chamber temperature from the thermometer and then read the closest humidity value from the calibration table (Greenspan's Calibration Table, NaCl or K2SO4 solution).
  11. Adjust the wet end (WET, gain) to correspond to the value given in the calibration table.