mechanical (including photocopying), nor may its contents be communicated to a third
party without prior written permission of the copyright holder.
The contents are subject to change without prior notice.
Please observe that this manual does not create any legally binding obligations for
Vaisala towards the customer or end user. All legally binding commitments and
agreements are included exclusively in the applicable supply contract or Conditions of
Sale.
Throughout the manual, important safety considerations are highlighted
as follows:
Warning alerts you to a serious hazard. If you do not read and follow
instructions very carefully at this point, there is a risk of injury or even
death.
Caution warns you of a potential hazard. If you do not read and follow
instructions carefully at this point, the product could be damaged or
important data could be lost.
Note highlights important information on using the product.
Chapter 1 ________________________________________________________ General Information
Feedback
Vaisala Customer Documentation Team welcomes your comments and
suggestions on the quality and usefulness of this publication. If you find
errors or have other suggestions for improvement, please indicate the
chapter, section, and page number. You can send comments to us by email: manuals@vaisala.com
Product Related Safety Precautions
The Vaisala HUMICAP® Humidity and Temperature Module HMM212
delivered to you has been tested for safety and approved as shipped from
the factory. Note the following precautions:
WARNING
CAUTION
CAUTION
Ground the product, and verify outdoor installation grounding
periodically to minimize shock hazard.
Do not modify the unit. Improper modification can damage the product
or lead to malfunction.
Do not touch the sensor element.
ESD Protection
Electrostatic Discharge (ESD) can cause immediate or latent damage to
electronic circuits. Vaisala products are adequately protected against
ESD for their intended use. However, it is possible to damage the product
by delivering electrostatic discharges when touching, removing, or
inserting any objects inside the equipment housing.
To make sure you are not delivering high static voltages yourself:
- Handle ESD sensitive components on a properly grounded and
protected ESD workbench. When this is not possible, ground yourself
to the equipment chassis before touching the boards. Ground yourself
with a wrist strap and a resistive connection cord. When neither of the
above is possible, touch a conductive part of the equipment chassis
with your other hand before touching the boards.
- Always hold the boards by the edges and avoid touching the
component contacts.
Recycling
Recycle all applicable material.
Dispose of batteries and the unit according to statutory regulations. Do
not dispose of with regular household refuse.
Regulatory Compliances
The Vaisala HUMICAP® Humidity and Temperature Module HMM212
complies with the following performance and environmental test
standards:
The emission and immunity tests have been performed according to
standard EN61326-1.
Table 3 Emission Tests
Test Setup According to
RF field emission CISPR 22 Class B (EN55022)
Conducted emissions CISPR 22 B (EN55022)
Table 4 Immunity Tests
Test Setup According to
Electrostatic discharge IEC 1000-4-2 (EN 61000-4-2)
Fast transient burst IEC 1000-4-4 (EN 61000-4-4)
RF field immunity IEC 1000-4-3 (EN 61000-4-3)
Conducted RF immunity
NOTE: cable length max. 8
meters
Surge IEC 1000-4-5 (EN 61000-4-5)
Voltage dips, short
interrupts
Chapter 1 ________________________________________________________ General Information
Patent Notice
The Vaisala HUMICAP® Humidity and Temperature Module HMM212
is protected by the following patents and patent applications and their
corresponding national rights:
Finnish patent 98861, French patent 6650303, German patent 69418174,
Japanese patent 3585973, UK patent 0665303, and US patent 5607564.
Trademarks
Vaisala Trademark is a registered trademark of Vaisala Oyj.
®
HUMICAP
is a registered trademark of Vaisala Oyj.
Warranty
Vaisala hereby represents and warrants all Products manufactured by
Vaisala and sold hereunder to be free from defects in workmanship or
material during a period of twelve (12) months from the date of delivery
save for products for which a special warranty is given. If any Product
proves however to be defective in workmanship or material within the
period herein provided Vaisala undertakes to the exclusion of any other
remedy to repair or at its own option replace the defective Product or part
thereof free of charge and otherwise on the same conditions as for the
original Product or part without extension to original warranty time.
Defective parts replaced in accordance with this clause shall be placed at
the disposal of Vaisala.
Vaisala also warrants the quality of all repair and service works
performed by its employees to products sold by it. In case the repair or
service works should appear inadequate or faulty and should this cause
malfunction or nonfunction of the product to which the service was
performed Vaisala shall at its free option either repair or have repaired or
replace the product in question. The working hours used by employees of
Vaisala for such repair or replacement shall be free of charge to the
client. This service warranty shall be valid for a period of six (6) months
from the date the service measures were completed.
This warranty is however subject to following conditions:
a) A substantiated written claim as to any alleged defects shall have
been received by Vaisala within thirty (30) days after the defect or
fault became known or occurred, and
b) the allegedly defective Product or part shall, should Vaisala so
require, be sent to the works of Vaisala or to such other place as
Vaisala may indicate in writing, freight and insurance prepaid and
properly packed and labelled, unless Vaisala agrees to inspect and
repair the Product or replace it on site.
This warranty does not however apply when the defect has been caused
through
a) normal wear and tear or accident;
b) misuse or other unsuitable or unauthorized use of the Product or
negligence or error in storing, maintaining or in handling the
Product or any equipment thereof;
c) wrong installation or assembly or failure to service the Product or
otherwise follow Vaisala's service instructions including any
repairs or installation or assembly or service made by unauthorized
personnel not approved by Vaisala or replacements with parts not
manufactured or supplied by Vaisala;
d) modifications or changes of the Product as well as any adding to it
without Vaisala's prior authorization;
e) other factors depending on the Customer or a third party.
Notwithstanding the aforesaid Vaisala's liability under this clause shall
not apply to any defects arising out of materials, designs or instructions
provided by the Customer.
This warranty is expressly in lieu of and excludes all other conditions,
warranties and liabilities, express or implied, whether under law, statute
or otherwise, including without limitation ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR OF FITNESS FOR A
PARTICULAR PURPOSE and all other obligations and liabilities of
Vaisala or its representatives with respect to any defect or deficiency
applicable to or resulting directly or indirectly from the Products supplied
hereunder, which obligations and liabilities are hereby expressly
cancelled and waived. Vaisala's liability shall under no cir-cumstances
exceed the invoice price of any Product for which a warranty claim is
made, nor shall Vaisala in any circumstances be liable for lost profits or
other consequential loss whether direct or indirect or for special damages.
This chapter introduces the features and advantages of the Vaisala
HUMICAP® Humidity and Temperature Module HMM212.
Introduction to HMM212
The HMM212 modules are designed especially for relative humidity
measurements in environmental chamber applications with high
temperature and humidity levels.
The HMM212 module is a microprocessor-based instrument with
temperature compensation in RH measurements. The module includes
separate 4 ... 20 mA loop powered RH and T channels. The humidity
probe length is an order-specified option. Furthermore, the customer can
also order the module with:
- a suitable cable length (0.65 m, 1.50 m or 3.0 m)
- a temperature loop current scaled for that particular application
(0 ... 100 °C, -20 ... +120 °C, -20 ... +180 °C, -40 ... +180 °C or
-70 ... +180 °C)
The HMM212 modules are connected to process control systems with
screw terminals. These versatile modules incorporate the
HUMICAP®180R humidity sensor, which uses an operating principle
based on changes in the capacitance of a thin polymer film as it absorbs
water molecules. The HMM212 modules measure temperature with the
reliable Pt 1000 sensor.
Chapter 3 ________________________________________ To Be Noted When Measuring Humidity
CHAPTER 3
TO BE NOTED WHEN MEASURING
HUMIDITY
This chapter describes issues that need to be noted in the measurement of
humidity.
In the measurement of relative humidity and especially in calibration, it
is essential that the temperature equilibrium is reached. Even a slight
difference in the temperature between the measured object and the sensor
causes an error. For example, at +20 °C (+ 68 °F) and 50 %RH, a
temperature difference of ±1 °C between the measured object and the
sensor causes an error of ±3 %RH. If relative humidity is 90 %RH, the
error is about ±5.4 %RH. A graph of the measurement error at 100 %RH
when the temperature difference between ambient air and the sensor is
1 °C is presented in Figure 1 on page 16.
The error is at its greatest when the temperature of the sensor differs from
that of the surroundings and the humidity is high. A difference of a few
degrees in temperature may cause water to condense on the sensor
surface. Efficient ventilation accelerates the evaporation of the condensed
water whereas in an unventilated space, it may take hours. The
HUMICAP
water has evaporated. Contaminated water condensing on the sensor may
shorten its life span and alter the calibration.
®
180R sensor returns to its normal functioning as soon as
This chapter provides you with information that is intended to help you
install this product.
Selecting Location
Finding a suitable site for HMM212 is important for getting
representative ambient measurements.
Select a place that gives a true picture of the environment or process and
is as clean as possible. Air should flow freely around the sensor.
Install the sensor head to a sufficient distance from the duct or chamber
walls. Make sure to insert enough cable to the same space with the probe
in order to prevent heat conduction.
This chapter contains information that is needed to calibrate this product.
Vaisala recommends a recalibration of the HMM212 module after six
months of use. After the first recalibration, the recommended calibration
interval is approximately 12 months. However, please note that these
intervals depend on the operating conditions and the required accuracy.
When calibrating humidity instruments, it is important that the probe, the
reference instrument, and the calibrator are in thermal equilib rium.
Therefore, always allow enough time for stabilization before starting the
actual calibration.
- Calibration in the chamber: leave the calibrator (for example, the
HMK15) in the chamber overnight with the chamber door open.
- Calibration of a humidity and temperature module: allow at least one
hour for the stabilization of the calibrator (for example, HMI41 with a
reference probe).
One-Point Humidity Calibration
With the HMI41 Indicator and Calibration
Cable
You can calibrate the HMM212 module with the HMI41 indicator and an
appropriate calibration cable (19164ZZ). Connect the cable to the test
connector of the HMM212 module and insert the jumper as indicated in
Figure 4 on page 22. For detailed instructions, see the following
documents:
- Vaisala HUMICAP® Indicator HMI41 and Probes HMP41/45/46
User's Guide
- Calibration of Digital Transmitters with Vaisala HUMICAP®
Humidity Indicator HMI41 Cables 19164ZZ and 25917ZZ User's
Guide
The following numbers refer to Figure 4 above:
1 = For calibration with the HMI41, insert the jumper as indicated
here.
2 = Calibration connector for the HMI41
The serial communication parameters are:
1200 bauds, no parity, 8 data bits, 1 stop bit
When the connection is being established, the message 'CON ERROR'
blinks on the HMI41 display for a couple of times after which
measurement readings appear. This is quite normal and requires no
action; however, if the message is not replaced by measurement readings,
it is an indication of an operation error.
Do not interrupt the calibration procedure. In case of an interruption or a
power failure, the normal mode is restored by completing the calibration
or resetting the module. Reset the module by switching off the supply
power of temperature channel.
During the calibration with HMI41, please note that temperature loop
current is not within the scaling.
With Pushbuttons and a Jumper
You can also perform the calibration with pushbuttons and a jumper on
the component board (see Figure 5 on page 24). In addition, you need a
digital multimeter (DMM). There are two push buttons (UP and DOWN)
and four pairs of pins (RH offset, RH gain, T offset, and T gain), which
are connected with the calibration jumper. Vaisala recommends using the
RH offset pins if the RH is less than 65 %RH and the gain pins if the RH
is greater than 65 %RH.
For example, to perform a one-point humidity calibration using saturated
NaCl salt solution at 75.5 %RH as a reference, do as follows:
1. Insert the probe into a NaCl salt chamber and let stabilize.
2. Connect a DMM to the RH current loop and wait until the reading
stabilizes.
3. Connect a jumper to the RH gain pins and adjust the DMM reading
with buttons UP and DOWN until the loop current corresponds to
75.5 %RH.
4. Disconnect the jumper.
Two-Point Humidity Calibration
You can also perform a two-point calibration with saturated salt
calibrators (for example HMK15), or you can send the instrument to
Vaisala or a Vaisala representative for recalibration. Figure 6 on page 26
illustr
ates the difference between offset and gain calibrations.
Two-Point Humidity Calibration Procedure
1. Leave the calibrator and the probe for at least 1 hour in the same
environment so that their temperatures have time to equalize. For
information on more accurate stabilization times, see Chapter 4,
Installation, on page 17.
2. Insert the probe into the measurem ent hole of the LiCl salt chamber
in the humidity calibrator.
3. Wait for 20 to 40 minutes.
4. Check the temperature and read the closest corresponding RH
value in the calibration table (Table 5 on page 25)
5. Connect the jumper to the RH offset pins (see Figure 5 below) and
adjust the output signal with push buttons to the value given in the
calibration table (Table 5 on page 25).
6. Insert the probe into the m easurement hole of the NaCl chamber.
7. Wait for 20 to 40 minutes.
8. Check that the reading corresponds within the desired accuracy to
the reading given in the calibration table. If not, connect the jumper
to the RH gain pins and adjust the reading with push buttons.
9. Check again the reading at the first point and repeat the procedure
if necessary.
T offset
RH gain (WET)
RH of fset (DRY)
T gain
Figure 5 Calibration Pins and Pushbuttons
With the jumper connected to the RH gain pins, each pressing of the UP
or DOWN button changes the value approximately 0.05 %RH at
75 %RH. With the jumper connected to the RH offset pins, each pressing
changes the value approximately 0.05 %RH.
With the jumper connected to the T offset pins, each pressing of the UP
or DOWN button changes the value 0.05 °C or 0.05 °F in all
temperatures. With the jumper connected to the T gain pins, each
pressing changes the value 0.05 °C or 0.05 °F in the temperature
currently prevailing in the process.
Table 5 Greenspan's Calibration Table with Output Values
According to the Chosen Scale
Temperature
LiCl
4 ... 20 mA mA 5.81 5.81 5.81 5.81
0 ... 20 mA mA 2.26 2.26 2.26 2.26
0 ... 1 V V 0.113 0.113 0.113 0.113
0 ... 5 V V 0.565 0.565 0.565 0.565
0 ... 10 V V 1.13 1.13 1.13 1.13
°C
°F
%RH
15
59
*)
20
68
11.3
25
77
11.3
30
86
11.3
35
95
11.3
Temperature
NaCl
4 ... 20 mA mA 16.10 16.08 16.05 16.02 15.98
0 ... 20 mA mA 15.12 15.10 15.06 15.02 14.98
0 ... 1 V V 0.756 0.755 0.753 0.751 0.749
0 ... 5 V V 3.780 3.775 3.765 3.755 3.745
0 ... 10 V V 7.56 7.55 7.53 7.51 7.49
°C
°F
%RH
15
59
75.6
20
68
75.5
25
77
75.3
30
86
75.1
35
95
74.9
*) If the LiCl solution is used or stored in temperatures below +18 °C (+64 °F), the equilibrium
humidity of the salt solution may change permanently.
The temperature channel of the HMM212 is very stable and the modules
have been calibrated at the factory. Unless there is a strong reason to
believe that the adjustments have changed, do not perform a temperature
calibration. This is a very demanding procedure and requires both
expertise and extremely accurate references. Furthermore, it is important
to allow enough time for the stabilization during calibration. If for some
reason, it is necessary to perform the temperature calibration, follow
attentively the instructions given below.
Temperature Calibration of an RH and T
Module
- Allow enough time for the instruments to stabilize to the temperature
in which calibration is performed.
- Connect a DMM to the temperature current loop.
- Connect a jumper to the T offset or the T gain pins. Adjust the reading
with UP and DOWN switches (see Figure 5 on page 24). Note that
during gain adjustment, the offset point does not change:
If the product needs repair, please follow the instructions below to speed
up the process and to avoid extra costs to you.
1. Read the section Warranty on page 11.
2. Contact a Vaisala Service Center or a local Vaisala representative.
The latest contact information and instructions are available from
www.vaisala.com. Addresses of the Service Centers are provided
in section Vaisala Service Centers on page 31.
Please have the following information on hand:
- serial number of the unit
- date and place of purchase or last calibration
- description of the fault
- circumstances in which the fault occurs/occurred
- name and contact information of a technically competent person
who can provide further information on the problem
3. Pack the faulty product in a strong box of adequate size, with
proper cushioning material to avoid damage.
4. Include the information specified in step 2 in the box with the
faulty product. Also include a detailed return address.
5. Ship the box to the address specified by your Vaisala contact.
Vaisala Service Centers perform calibrations and adjustments as well as
repair and spare part services. See contact information below.
Vaisala Service Centers also offer accredited calibrations, maintenance
contracts, and a calibration reminder program. Do not hesitate to contact
them to get further information.
Chapter 8 ____________________________________________________________ Technical Data
CHAPTER 8
TECHNICAL DATA
This chapter provides the technical data of the product.
Specifications
Table 7 Relative Humidity Specifications
Property Description / Value
Measurement range 0 ... 100 %RH
Accuracy (including non-linearity,
hysteresis and repeatability)
Response time (90%) at +20 °C in still air
(with sintered filter)
Typical temperature dependence of
electronics
Sensor
±2 %RH (0 … 90 %RH)
±3 %RH (90 … 100 %RH)
60 s
0.02 %RH/°C
HUMICAP
180R
Table 8 Temperature Specifications
Property Description / Value
Measurement range -70 ... +180 °C
Typical accuracy of electronics at +20 °C ±0.1 °C
Typical temperature dependence of
electronics
Sensor Pt 1000 RTD 1/3 Class B IEC 751
0.0025 °C/°C
Table 9 Analog Output Specifications
Property Description / Value
Two analog outputs 4 ... 20 mA
Ch1: RH
Ch2: T
Typical accuracy ±0.1 %FS
Resolution Ch1: 0.025 %RH
Ch2: 0.01 %FS
Typical temperature dependence 0.005 %FS/°C
Operating temperature range
Probe
Electronics
Storage temperature range (electronics) -40 … +70 °C
Sensor protection:
Standard
Connections Screw terminals for