Vaisala HM70 indicator + HMP75 probe

Contact Instrument Solutions


The Vaisala HUMICAP handheld humidity & temperature meter HM70 is designed for demanding humidity measurements. The HM70 includes an MI70 indicator and an optional probe depending on the application. The HM70 incorporates the latest generation of the Vaisala HUMICAP sensor and it is reliable with better than ever long-term stability. Additionally, it has a sensor that copes well with chemical interference and provides accuracy that lasts in demanding conditions.


Three probes to choose from

The HMP75 is a general purpose probe whereas the HMP76 is a long, stainless steel probe especially suitable for spot-checking in ducts. The HMP77 is a small probe at the end of a 5-meter cable. The probe is ideal for difficult-to-reach areas and for on-site calibration of Vaisala's process transmitters. In addition, the HM70 supports the use of Vaisala's dewpoint, carbon dioxide and moisture in oil probes, allowing measurements in several multiparameter applications.

MI70 Link Software

The optional MI70 Link Windows software and the USB connection cable form a practical tool for transferring logged data and real time measurement data from the HM70 to a PC.

Please note: The MI70 Link Windows software is available as a free download from the Vaisala website, to visit please click here.

For technical data please refer to PDF datasheet.

IMPORTANT NOTE: The Instrument Hire models includes the HMP75 type probe and the MI70 Link software / USB cable. When purchasing an instrument the HM70 includes an MI70 indicator and an optional probe depending on the application.


MI70 measurement indicator

Display LCD with backlight, graphic trend display of any parameter, character height up to 16 mm

Maximum number of probes 2

Power supply Rechargeable NiMH battery pack with AC adapter or 4xAA-size alkaline, type IEC LR6 0

Analogue output 0 to1 VDC

Output resolution 0.6 mV

PC interface MI70 Link software with USB or serial port cable

Data logging capacity 2700 points

Alarm Audible alarm function

Operating temperature range - 10 to + 40 °C

Operating humidity range Non-condensing

Housing classification IP54

Battery operation time Continuous use 48 h typical at + 20 °C

Data logging Up to a month, depending on logging interval

HMP75, HMP76 and HMP77 probes

Humidity measurement range 0 to 100 % rh

Accuracy (including nonlinearity, hysteresis and repeatability):

at + 15 to + 25 °C ± 1 % rh (0 ... 90 % rh) ± 1.7 % rh (90 ... 100 % rh)
at - 20 to + 40 °C ± (1.0 + 0.008 x reading) % rh
at - 40 to + 180 °C ± (1.5 + 0.015 x reading) % rh

Factory calibration ± 0.6 % rh (0 to 40 % rh) uncertainty (+ 20 °C) ± 1.0 % rh (40 to 97 % rh)

Response time @ (90 %) at + 20 °C in still air:
HMP75 (with standard plastic grid) 17 s
HMP76 (with standard sintered bronze filter) 60 s
HMP77 (with standard plastic grid and stainless steel netting) 50 s

Sensor type HUMICAP 180R with a typical long-term stability better than 1 % rh / year

Temperature measurement range:
HMP75 - 20 to + 60 °C
HMP76 - 50 to + 120 °C short time - 50 ... + 180 °C
HMP77 - 70 to + 180 °C

Accuracy at + 20 °C ± 0.2 °C

Support documents

  • Download
  • Category
  • File type
  • Download
Vaisala HM70 user manual.pdf Vaisala HM70 user manual
Technical document
File type
Adobe Acrobat
Download (1 MB)
Vaisala HM70 data sheet.pdf Vaisala HM70 data sheet
Technical document
File type
Adobe Acrobat
Download (2 MB)
Vaisala Humicap technology application note.pdf Vaisala Humicap technology application note
Technical document
File type
Adobe Acrobat
Download (274 KB)