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HMI41 Indicator and HMP42/HMP46 Probes
The Vaisala HUMICAP® Humidity
Indicator HMI41 fitted with the Vaisala
HUMICAP
Probes HMP42 or HMP46 can be used
for spot checking and field calibration
applications.
In addition to displaying the humidity
and temperature readings, the HMI41
indicator calculates dew point and wet
bulb temperature, absolute humidity
and mixing ratio.
The indicator has an easy-to-read two
line liquid crystal display. The display
units (metric or non-metric) are easily
selected.
These features, plus fast response
time, high measurement accuracy and
excellent stability, as well as the unique
properties of the probe chosen – either
the HMP42 or the HMP46 – make
the HMI41 indicator and HMP42/46
combination an ideal choice for the
most demanding applications.
®
Humidity and Temperature
Features/Benefits
RH measurement range
▪
0 ... 100 %RH
Temperature measurement
▪
range -40 ... +100 °C
(-40 ... +212 °F), with the
HMP46 only for short periods
up to +180 °C (+356 °F)
Calculates dew point, wet bulb
▪
temperature, absolute humidity
and mixing ratio
Versatile and easy-to-use
▪
Incorporates Vaisala HUMICAP®
▪
Sensor
Excellent stability
▪
Data collection with serial line
▪
NIST traceable (certificate
▪
included)
Optional carrying case and
▪
calibration cable
Vaisala HUMICAP®
Humidity and Temperature
Probe HMP42
The HMP42 probe can be used for spot
checking humidity and temperature
in applications which require an
extremely thin probe. Typically the
probe is used for monitoring the drying
of structures during construction or
after water damage. It is ideal to be
used when measuring in any tight
places, in ducts or chambers or, for
example, under a linoleum floor.
The probe diameter is only 4 mm,
allowing access into very small, tight,
and hard-to-reach spaces.
Vaisala HUMICAP®
Humidity and Temperature
Probe HMP46
Typical applications for the HMP46
are plant maintenance, installation
and inspection of air conditioning
systems, production and storage areas
and production processes. The HMP46
operates in full humidity range of
0 ... 100 %RH. The temperature range
is from -40 to +100 °C (-40 ... +212 °F).
For short periods of time, the probe
can withstand temperatures up to
+180 °C (+356 °F).
The HMP46 probe is solid and
rugged. Its stainless steel probe is
made to withstand rough handling in
mechanically demanding applications.
The probe’s long shaft can also reach
otherwise unreachable places.
High Performance Sensor
The HMP42/46 probes incorporate
Vaisala HUMICAP
has high accuracy, excellent long-term
stability and negligible hysteresis.
In addition, the sensor is insensitive
to dust, particulate dirt and most
chemicals.
®
Sensor. This sensor
The Vaisala HUMICAP® Humidity
Indicator HMI41 equipped with the
Vaisala HUMICAP
Temperature Probe HMP42 – an
extremely thin probe allowing access
into very small, tight, hard-to-reach
spaces.
The Vaisala HUMICAP® Humidity
Indicator HMI41 equipped with the
Vaisala HUMICAP
Temperature Probe HMP46 – a rugged
stainless steel probe for mechanically
demanding and high temperature
applications.
®
Humidity and
®
Humidity and

Technical Data
HMI41 Indicator
Calculated variables dew point temperature, absolute humidity,
wet bulb temperature, mixing ratio
Resolution 0.1 %RH; 0.1 °C/°F
Power supply 4 batteries, type AA (LR 6)
Battery operation time
(alkaline batteries) 72 h continuous use
Auto-off function
Operating temperature -20 ... +60 °C (-4 ... +140 °F)
Storage temperature -40 ... +70 °C (-40 ... +158 °F)
Display two line LCD
Housing material ABS plastic
Housing classification IP53 (with connectors blocked)
Weight (incl. batteries) 300 g
Maximum measurement error of indicator at +20 °C
humidity ±0.1 %RH
temperature ±0.1 °C (±0.18 °F)
HMP42 Probe
HUMIDITY
Measurement range 0 ... 100 %RH
Accuracy (incl. non-linearity, hysteresis and repeatability)
at +20 °C (+68 °F)
0 … 90 %RH ±2 %RH
90 … 100 %RH ±3 %RH
Factory calibration uncertainty (+20 °C / +68 °F)
0 … 15 %RH ±1 %RH
15 … 78 %RH ±1.5 %RH
Temperature dependence of electronics ±0.05 %RH/°C
Typical long-term stability better than 1 %RH per year
Response time (90%) at +20 °C in still air 30 s
TEMPERATURE
Measurement range HMP42 -40 ... +100 °C (-40 ... +212 °F)
Temperature accuracy over measurement range
∆°C
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-40 -20 0 20 40 60 80 100
T/° C
Temperature sensor Pt100 RTD Class F0.3 IEC 60751
HMP46 Probe
HUMIDITY
Measurement range 0 ... 100 %RH, non-condensing
Accuracy (incl. non-linearity, hysteresis and repeatibility)
at +20 °C (+68 °F)
0 … 90 %RH ±1 %RH
90 … 100 %RH ±2 %RH
Factory calibration uncertainty (+20 °C / +68 °F)
0 … 15 % RH ±1 %RH
15 … 78 %RH ±1.5 %RH
Temperature Dependence
error %RH
2
1.5
1
0.5
0
-0.5
-1
-1.5
-2
-40
-20 20 60
0
40
T/°C
Typical long-term stability better than 1 %RH per year
Response time (90%)
at +20 °C in still air w/sintered filter 15 s
TEMPERATURE
Continuous measurement -40 ... +100 °C (-40 ... +212 °F)
Short-term measurement -40 ... +180 °C (-40 ... +356 °F)
Temperature accuracy at +20 °C (+68 °F) ±0.2 °C (±0.36 °F)
Temperature accuracy over the measurement range
°C
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-40 -20 0 20 40 60 80 100 120 140 160
T/°C
Temperature sensor Pt100 RTD Class F0.1 IEC 60751
100
for temporary
use only
120
140
16080
180
180

Technical Data
General for Probes
Cable length 1500 mm; extended spiral cable
Operating temperature range
for electronics -20 ... +60 °C (-4 ... +140 °F)
Housing material
electronics housing ABS plastic
probe stainless steel
Housing classification
electronics IP65 (NEMA 4)
HMP42 sensor protection
steel grid 19867HM
membrane, tube set (5 pcs) 19858HM
HMP46 sensor protection
sintered filter 0195
optional membrane filter,
(max +80 °C / +176 °F) 10159HM
plastic grid, (max +80 °C / +176 °F) 6221
Weight
HMP42 200 g
HMP46 450 g
Electromagnetic compatibility Complies with EMC standard
EN61326-1, Portable Equipment.
Accessories
Transmitter calibration cables
HMT330, HMT120/130 25917ZZ
HMT360 25916ZZ
HMM210 19164ZZ
HMD/W60/70 19116ZZ
Carrying case for HMI41 & HMP42/46
plastic 210614
aluminum MI70CASE2
Serial communication cable 19446ZZ
HMP42
Calibration adapter HM37067
Rubber sleeve set 19809HM
Dimensions
Dimensions in mm.
HMI41 HMP42 HMP46
320
88 30200
ø18.5
318
ENTERMODE
HOLD ON/OFF
MIN/MAX
125
75
80
37
13
106
30
HUMICAP® is a registered trademark of Vaisala.
235
ø4
ø18.5
13
ø21
38
ø12
ø2 1
13
106
3 0
38
Ref. B211141EN-B ©Vaisala 2012
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of Vaisala or its individual partners. The reproduction, transfer,
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in any form without the prior written consent of Vaisala is strictly
prohibited. All specifications — technical included — are subject
to change without notice.
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