HID Lumidigm M Series Quick setup guide

Lumidigm M-Series M3xx Modules
Mechanical Integration Guide
PLT-02217, Rev. A.0
December 2014
hidglobal.com
Lumidigm

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 2 of 28
Contents
1Introduction.............................................................................................................................. 4
1.1 M-Series Modules Overview .......................................................................................................................4
2Human Factor Considerations ............................................................................................ 5
2.1 Summary of human factor considerations ........................................................................................... 5
2.2 Human Factor Design Discussion ............................................................................................................6
3Mounting Considerations ..................................................................................................... 8
3.1 Presence Detection Illumination System...............................................................................................8
3.2 Sensor Head .....................................................................................................................................................9
3.3 Sensor Head Mounting Summary............................................................................................................13
3.4 ECU - M30x..................................................................................................................................................... 14
3.4.1 Connectivity........................................................................................................................................................... 15
3.5 ECU - M31x .......................................................................................................................................................16
3.5.1 Connectivity........................................................................................................................................................... 17
3.5.2 GPIO Controls........................................................................................................................................................ 18
3.6 ECU-to-Sensor Connection .......................................................................................................................19
4Environmental Considerations .........................................................................................20
4.1 Summary of Environmental Considerations ..................................................................................... 20
4.2 Example Outdoor Enclosure .....................................................................................................................21
4.3 Design Goals ...................................................................................................................................................21
4.3.1 Example of Outdoor Enclosure External Environment Requirements............................................. 21
4.3.2 M3xx Specifications ........................................................................................................................................... 22
4.4 Operating Temperature Control Considerations .............................................................................22
4.5 Water and Dust Sealing Considerations..............................................................................................24
4.6 Background Light Considerations .........................................................................................................25
4.7 Condensation Considerations..................................................................................................................26
5Conclusion .............................................................................................................................. 27

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 3 of 28 December 2014
Copyright
©2014 HID Global Corporation/ASSA ABLOY AB.
All rights reserved. This document may not be reproduced, disseminated or republished in
any form without the prior written permission of HID Global Corporation
Trademarks
HID GLOBAL, HID, and the HID logo are the trademarks or registered trademarks of HID
Global Corporation, or its licensors, in the U.S. and other countries.
Lumidigm is a registered trademark of Lumidigm, Inc.
Revision History
Date
Description
Version
12/16/14 First release as part of HID Global (1.6) A.0
Contacts
For additional offices around the world, see www.hidglobal.com corporate offices.
North America & Corporate Lumidigm
611 Center Ridge Drive
Austin, TX 78753
USA
Phone: [phone]
Fax: [phone]
For Lumidigm specific issues:
Website:
http://www.hidglobal.com/lumidigm-technical-support
Email: [e-mail]
Phone: [phone]
HID Global Customer Support: support.hidglobal.com

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 4 of 28
1
Introduction
Thank you for your interest in the Lumidigm M-Series M3xx modules. After a brief overview,
there are three main sections in this document. First we discuss the human factor
considerations that must be taken into account when designing the ergonomics of a
successful M-Series module-based product. Second, we provide detailed information and
best practices for mounting that should expedite successful M-Series module-based
product design. Finally, because every application is different, we discuss general
environmental design considerations.
Note that the M-Series currently has two product lines: the M30x and the M31x. Relevant
differences are discussed clearly throughout this document.
1.1
M-Series Modules Overview
The M-Series modules are multispectral imaging single finger biometric readers. They each
consist of a sensor head and associated electronics, called the Electronic Control Unit
(ECU), connected together with a shielded flat ribbon cable. Together these three parts
constitute the Lumidigm M-Series modules.
The M-Series modules are designed to be incorporated into products where a reliable
biometric with Real World Performance™ is required to meet end-customer performance
and durability requirements. This document describes the mechanical integration
guidelines and requirements necessary to incorporate the M-Series modules into a product
design.
Figure 1: Lumidigm M30x module
The M3xx sensor head is a sophisticated, self-aligned, reliable optical device with a durable
glass platen surface and an integrated imaging and illumination system. The illumination
system has one-finger presence detection (PD) LED and four image capture LEDs. When
the sensor is armed (active and waiting to detect a finger) the PD LED (blue) is on. As a
finger approaches the platen, it is illuminated by the blue LED and finger placement data
are streamed to the ECU. Image processing on the ECU confirms finger placement and
then rapidly captures two fingerprint images with different illumination states. These two
images are processed by the ECU to produce a conventional fingerprint. Lastly, the ECU
provides biometric feature extraction, 1:1 matching, 1:N searches, and biometric template
storage and management functions.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 5 of 28 December 2014
2
Human Factor Considerations
To achieve the highest biometric performance and the fastest transaction times, the
enclosure design incorporating the M3xx module must consider human factors.
For a biometric device, it is important to take a design approach that makes finger
placement intuitive and naturally guides finger placement to rapidly achieve optimal finger
position. Optimal placement is when the core of the fingerprint is in the center of the platen
area and the finger is parallel to the platen surface. Ergonomic features around the platen
area combined with the overall placement of the enclosure are used to insure a high
performance system.
The guidance in this document is written to support consistent finger placement. However,
Lumidigm fingerprint sensors and matching algorithms must take into account minor
variance in finger placement from placement to placement. Thus, it is absolutely critical
that the enrollment policy for any application demands complete separation of finger
placement events; i.e., multiple images must not be taken from a single placement during
enrollment.
2.1
Summary of human factor considerations
•Enclosure ergonomic features should facilitate quick, optimal, and repeatable
placement of the finger.
•Fingertips should be centered as closely as practical in the platen area such that the
fingerprint core is in the center of the platen.
•The enclosure design and placement of the enclosure should allow the fingers to be
as flat as possible when placed on the platen.
•Special considerations should be made for small fingers, large fingers, and fingers
with long fingernails.
•Note that thumb placement considerations are significantly different from placement
considerations for the other fingers
The opposing nature of the thumb with respect to the other fingers dictates a
different orientation of the hand with respect to the platen.
The surface area of the thumb is generally larger than the platen. This can
create a placement matching score dependence since the area captured at
enrollment may be significantly different than the area captured during
verification
•An aggressive ergonomic feature that is elliptical in cross-section and conical
perpendicular to the platen (getting wider as distance from the platen increases) is
preferred. However the platen opening should be rectangular so that it can be sealed
properly to the M3xx sensor head.
•Ergonomic features should be aggressive and enforce or encourage stable finger
placement such that, once placed, the finger does not move in any direction for
~150ms.
•Fingers should approach the module from the front side and be perpendicular to the
platen edge approached. This orientation is required to avoid a placement where the
blue PD LED illumination pattern is directed towards the user. The front side of the
M3xx sensor head is the side directly opposite the flex cable connector.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 6 of 28
•Enclosure materials and ergonomic features should be kept as thin as possible
around the platen area to allow easy contact with the platen and avoid the creation
of a depression so deep that finger–platen contact is difficult to achieve.
•If the enclosure will be placed in direct sunlight, the enclosure should shade the
platen surface to prevent solar heat gain from making the platen temperature high
enough to be uncomfortable (>40°C).
•Platen heating should be considered if the enclosure is intended to operate in
temperatures approaching or below 5°C to allow for user comfort.
2.2
Human Factor Design Discussion
•Biometric performance is dependent on the orientation of the user’s finger with
respect to the platen surface at the time of capture. The sensor enclosure design
must enforce overall placement and orientation of the finger with respect to the
platen. This portion of the enclosure design is critical to attaining high levels of
biometric matching performance as well as rapid and error-free transaction rates.
•The overall design approach should be to design an ergonomic feature on the
exterior surface of the enclosure that facilitates user–sensor interactions that are
convenient and comfortable for the user while at the same time guiding user finger
placement towards the center of the sensor platen. An example is shown in Figure 2.
•Because performance is improved when users correctly place the finger flat on the
platen, the vertical placement of the sensor with respect to the average person’s
height needs to be considered. If the enclosure is placed below waist height, tilting
the front of the platen surface upward to meet the finger should be considered. If the
placement is significantly above waist height, the front of the platen surface should
be tilted downward to meet the natural angle of the finger when presented to the
enclosure.
•The mechanical design of the ergonomic features provided by the enclosure should
encourage or enforce finger placement such that the fingerprint core is near the
center of the platen on every touch. While the length and width of fingers varies
significantly among individuals, as do the distances from knuckle to core point and
core point to tip, finger physiology is such that the fingerprint core point is very
nearly aligned with the thickest part of the fingertip, especially in a side-to-side
direction. Therefore, an ergonomic feature that is elliptical in cross-section and
conical perpendicular to the platen (getting wider as distance from the platen
increases) as shown in Figure 2 tends to direct human behavior to comfortably and
naturally align the fingerprint core point with the center of the platen.
Figure 2: Example ergonomic feature
•In addition to promoting correct alignment, the ergonomic feature should encourage

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 7 of 28 December 2014
or enforce stable placement so that once a finger is placed, subsequent movement is
minimized for about 150ms.
•The actual opening in the ergonomic feature that is in contact with the M3xx sensor
head should remain rectangular to provide a reliable sealing surface between the
ergonomic and the sensor head. The sealing surface is shown in the upper right of
Figure 7 and the dimensions of the sealing area are shown in the upper left portion of
Figure 7.
•The ergonomic feature shown in Figure 2 consists of an elliptical opening designed to
encourage finger placement such that the core of the fingertip is centered on the
platen area. In the Figure, the finger approaches from the left and the higher wall on
the right (sensor back) side is meant to stop additional forward motion, while the
lower entry wall is meant to insure full finger contact with the sensor platen area. And
finally the rectangular sealing surface aligns to the M3xx sensor head sealing area. If
an IP65-rated enclosure is required, an additional gasket would be added between
the M3xx sensor head and the enclosure ergonomic feature shown.
•Care must be taken to place the M3xx sensor head in the enclosure such that the
platen surface is as close as possible to the enclosure’s external surface. A deep
depression at this interface may collect water and other contaminants and impede
finger contact with the platen. If the enclosure will be exposed to rain, enclosure
features that passively drain the platen surface should be considered.
•The final human factor design consideration is environmental. Solar heat gain at the
platen surface can increase platen temperature to levels to that uncomfortable to
touch. The sensor platen surface should be shaded by the enclosure from direct
sunlight through a combination of enclosure features as well as the placement of the
enclosure itself in the environment.
Lumidigm has experience designing ergonomic features that promote high biometric
system performance and should be consulted for this portion of the enclosure design.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 8 of 28
3
Mounting Considerations
3.1
Presence Detection Illumination System
The PD illumination system is directional and the user must approach the sensor from the
correct direction, the side opposite of where the flex cable enters the M3xx sensor head.
The mechanical design of the enclosure should enforce this approach direction. If the
approach direction is rotated by 180 degrees, the blue light will be directed toward the user
and will impact overall user experience with the product. In Figure 3 below, the correct user
approach direction is from left to right with the blue light directed towards the right (away
from the user).
Figure 3: Presence detection illumination pattern
The blue PD LED is illuminated when the sensor is armed. The enclosure design and the
placement of the enclosure need to accommodate the emission from this source. The
duration of the PD emission is application-dependent. In applications where the transaction
is initiated by touching the sensor, the blue PD LED will be illuminated constantly. In
applications where some other action initiates the transaction (for example, entering a PIN
on a keypad) the blue PD LED will only be active from this event until a fingerprint is
captured. Figures 4 and 5 provide details of the PD illumination pattern.
Flex Cable connector

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 9 of 28 December 2014
Figure 4: PD
illumination pattern,
front view
Figure 5: PD illumination pattern,
side view
3.2
Sensor Head
The M30x and the M31x product lines use the same sensor head. Figure 6 shows a cutaway
view of the M3xx sensor head showing the platen area, enclosure, and an assembly
consisting of a PCB with the imager and LEDs and a plastic element that contains lenses for
the LEDs and the imager itself. On the interior of the enclosure are several mirrors which
are used with the LED lenses to evenly illuminate the platen surface.
Figure 6: Sensor head detail

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 10 of 28
The enclosure is constructed from plastic which can be deformed by incorrect or poorly-
designed mounting. Thus, while the design itself is resilient, care must be taken while
mounting to ensure that pressure is sufficient to seal the platen area but not so excessive
that the M3xx sensor head enclosure is deformed.
The overall dimensions of the M3xx sensor head are shown in Figure 7 and a complete 3D
CAD model of both the M3xx sensor head (as well as the M30x and M31x ECUs) are
available from Lumidigm to support design activities.
Figure 7: Sensor head dimensions
The top surface of the Lumidigm sensor head has been designed to satisfy the
requirements of International Protection Rating 65 (IP65). The nature of the interface
between the top surface of the sensor and the customer’s enclosure as well as all the
design elements of the enclosure would determine the IP rating of the resulting
construction. Because the M3xx platen seal is IP65, enclosures can be designed up to this
rating.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 11 of 28 December 2014
It is strongly suggested that the customer mechanical design be completed in a way such
that the capture features used to secure the M3xx sensor head to the enclosure have
positive stop features so that the pressure set can be reliably achieved without careful
control of retaining screw torque. An example capture mechanism is shown in Figure 8.
Figure 8: Example customer mounting
The arrangement in Figure 8 consists of 1) a clip attached to the M3xx sensor head, mating
with its exterior features and 2) screws securing this clip to an example customer enclosure
where positive stop features on the enclosure terminate compression of the sensor head
when the clip and the enclosure are in contact. The dimensions, tolerances, and selection of
gasket material sealing the M3xx sensor platen area against the enclosure are critical
elements of the enclosure design.
Alternatively, a cup shape capturing the bottom of the sensor head and providing
mounting holes and features could be used in place of the clip-style approach shown in
Figure 8.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 12 of 28
The Lumidigm M3xx product line includes sensors with an enclosure. These products use
the mounting technique described in Figure 8. The details of the clip used in this design are
shown in Figure 9. The clip material is a flexible plastic that opens sufficiently to slide into
place over the M3xx sensor head enclosure and securely grip the mounting features
present.
Note:
M3xx modules do not ship with a mounting clip. 3D CAD models and
samples of the clip shown are available from HID Global.
Figure 9: Example M3xx sensor head retaining clip
Once exterior features are determined, the next consideration is to determine the nature of
the seal to be used between the sensor platen area and the internal surfaces of the features
which capture and attach the M3xx sensor head to the customer enclosure. Once the
overall sealing strategy and rating requirements are determined and a gasket material is
selected, the next consideration is to determine the pressure set of the gasket required to
achieve the seal rating required.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 13 of 28 December 2014
Once the pressure set and compressive properties of the gasket material are determined,
the final design consideration is reviewing the overall design for part-to-part tolerances so
that when the M3xx is secured to the enclosure, the required minimum gasket pressure is
achieved for the loosest part-to-part stack up. In addition, the tightest part-to-part stack up
should not exceed the maximum pressure allowable on the M3xx sensor head platen with
respect to the M3xx sensor head mounting features of 18psi. Figure 10 provides an example
of a positive stop design using the mounting ring shown in Figure 9.
Figure 10: Example mounting, detail
3.3
Sensor Head Mounting Summary
The features that capture and hold the M3xx sensor head should be designed to reliably
achieve the customer-required solid and liquid intrusion ratings.
The area around the platen should not allow standing water to accumulate or provide areas
that trap dust and other debris. Tilting the platen surface to provide drainage should be
considered when the enclosure is placed outdoors and exposed to precipitation.
The design should make allowances for easy cleaning of the platen surface.
The mounting method should be a positive stop design so that the reliability of the seal is
independent of manufacturing technique.
Allowances for the connecting cables and strain relief of those cables must be considered.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 14 of 28
3.4
ECU - M30x
Note:
This section applies to the M30x module ECU only. If you are designing for an M31x
module, please refer to the M31x ECU discussion that follows this section.
The M30x ECU dimensions are shown in Figure 11. The ECU should be placed in proximity
(both distance and orientation) to the sensor head to allow for proper installation and
routing of the flex cable that connects these two components of the M30x. The ECU is a
printed circuit board (PCB) with components on both sides. Wiring for power and I/O
interfaces are available at connectors, perpendicular to the PCB. Allowances for wiring
need to be made when considering the M30x ECU mounting strategy.
Figure 11: M30x ECU dimensions
The total ECU thickness with components and connector receptacles is 9.17mm. The
connector side thickness is 5.6mm with respect to the PCB surface and the shield side
thickness is 2mm with respect to the PCB surface. The PCB itself is 1.59mm thick. As with
the sensor head, a complete 3D model is available from Lumidigm to facilitate mechanical
design elements of the customer enclosure required to capture and secure the M30x ECU.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 15 of 28 December 2014
3.4.1
Connectivity
Detail for M30x ECU connectivity is provided in Figure 12 and in the chart, both below:
Figure 12: M30x ECU connector positions J3, J4, and J7
Connector Position J3
GPIO
Mating Hirose connector housing p/n is DF13-7S-1.25C with 26-30AWG crimp
terminal p/n DF13-2630SCF.
J3-1 = GND
J3-2 = N/C
J3-3 = N/C
J3-4 = Program Flag 10
J3-5 = Program Flag 11
J3-6 = Program Flag 12
J3-7 = Program Flag 13
Connector Position J4
USB connection. Five pin header.
Mating Hirose connector housing p/n is DF13-5S-1.25C with 26-28AWG crimp
terminal p/n DF13-2630SCF.
J4-1 = 5VDC
J4-2 = Data Minus (differential signal)
J4-3 = Data Plus (differential signal)
J4-4 = Ground (only if J7-4 is unused)
J4-5 = Shield

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 16 of 28
Connector Position J7
RS232 & Alternate Power.
Mating Hirose connector housing p/n is DF13-4S-1.25C
with 26-28AWG crimp terminal p/n DF13-2630SCF.
J7-1 = RS232 RD
J7-2 = RS232 TD
J7-3 = Ground
J7-4 = 5VDC (only if J4-1 is unused)
3.5
ECU - M31x
Note:
This section applies to the M31x module ECU only. If you are designing for an M30x
module, please refer to the M30x ECU discussion that precedes this section.
The M31x ECU dimensions are shown in Figure 13. The ECU should be placed in proximity
(both distance and orientation) to the sensor head to allow for proper installation and
routing of the flex cable that connects these two components of the M31x. The ECU is a
printed circuit board (PCB) with components on both sides. Wiring for power and I/O
interfaces is attached to connectors, perpendicular to the PCB. Allowances for wiring need
to be made when considering the M31x ECU mounting strategy.
Figure 13: M31x ECU dimensions
The total ECU thickness with components and connector receptacles is 3.36mm. The PCB
itself is 1.59mm thick. As with the sensor head, a complete 3D model is available from
Lumidigm to facilitate mechanical design elements of the customer enclosure required to
capture and secure the M31x ECU.
Note:
The M310 OEM Module does NOT meet FCC emissions standards and must be
shielded in a grounded enclosure.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 17 of 28 December 2014
3.5.1
Connectivity
Detail for M31x ECU connectivity is provided in Figure 14 and in the chart, both below:
Figure 14: M31x ECU connector positions
Connector Position MH
Red MH2 +5V (USB)
White MH3 D- (USB)
Green MH4 D+ (USB)
Black MH5 GND (USB)
MH7 GPO #1 through 430 ohm resistor
MH8 5VDC
MH9 GPO #2 through 430 ohm resistor
Note:
Customer provides cables or wires.
Note:
Cable shield ground should be connected to enclosure ground. The enclosure ground
must be close to the M31x ECU to insure signal integrity.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 18 of 28
3.5.2
GPIO Controls
User LEDs can be turned on/off on for M31x products. Sample code follows. “First”
corresponds to the MH7 control, “Second” corresponds to the MH9 control. These controls
are GPIO ports on a Xilinx part; 3.3V for VOH. “ON” means the output is low; when an LED
is connected between this port and 5V, current will flow. Note that the forward voltage
drop of a red LED (0.7V) is not adequate for the output to turn the LED fully off in the HI
state; an additional diode drop in series is recommended.
uchar mask = 0x00;
rc = V100_Get_GPIO(pDev, mask); // Get the mask
mask = 0x01; // First on 0001
rc = V100_Set_GPIO(pDev, mask);
Sleep(500);
mask = 0x00;
rc = V100_Set_GPIO(pDev, mask); // Turn off All
mask = 0x02; // Second on 0010
rc = V100_Set_GPIO(pDev, mask);
Sleep(500);
mask = 0x00;
rc = V100_Set_GPIO(pDev, mask); // Turn off All
mask = 0x03; // First and Second on 0011
rc = V100_Set_GPIO(pDev, mask);
Sleep(500);
mask = 0x00;
rc = V100_Set_GPIO(pDev, mask); // Turn off All

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
Page 19 of 28 December 2014
3.6
ECU-to-Sensor Connection
The M3xx is shipped as three separate components: the ECU, the sensor head, and the
connecting flex cable. Care must be taken to assemble the unit correctly to avoid damage
to the components. Figure 15 shows the proper installation orientation for the flex cable.
Care should be taken to avoid creating a crease in the flex cable, or excessively bending
the cable during handling or as a result of the mounting strategy used.
Figure 15: Flex cable installation
If the cable is not secured, it is possible for the cable to rotate with respect to the
connector. In this event, power events can disrupt the calibration data or ultimately cause a
hardware failure in the sensor head.
We recommend using hot glue to secure the flex cable to the connector. When assembling,
(1) place components in final assembly positions in the enclosure; (2) visually verify that the
flex cable is fully seated in the connector and not rotated as shown in Figure 16a; and (3)
apply hot glue to the flex cable / connector interface so that movement or loads on the flex
cable will not lead to cable rotation (Figure 16c).
Warning:
Do not glue the black flip-up bail (locking tab) as shown in Figure 16b.
Figure 16: Securing the flex cable
The black flip-up bail should be locked in place by applying equal pressure on both sides.
Operator training is imperative to get a consistent clamping pressure.

Lumidigm M-Series M3xx Modules Mechanical Integration Guide, PLT-02217, Rev. A.0
December 2014 Page 20 of 28
4
Environmental Considerations
Previous sections provided mounting approaches that result in an IP65-rated seal where
the M3xx platen area meets the external environment. This section provides additional
design guidance for engineers responsible for designing an outdoor enclosure containing
the M3xx.
Disclaimer
- The information provided in this section is for design guidance only and is
provided “as-is” with no warranties.
Disclaimer
- Lumidigm Inc. warrants that the M3xx module will meet all its specifications
when operated within the specified operating conditions. If the unit is operated outside
these conditions this warranty is voided.
Assumption
- An enclosure containing an M3xx will have electronics and perhaps an
exposed display screen. In this design guide we assume that M3xx specifications are
representative of the other enclosure components.
4.1
Summary of Environmental Considerations
The entire enclosure should be sealed from liquid water and dust intrusion to IP65. It should
restrict water vapor transfer.
A desiccant should be included in the interior of the enclosure to remove most of the water
vapor present during manufacture.
Irrespective of human comfort factors, the enclosure air temperature should be controlled
when the external operating temperature is < 0°C.
If no supplemental platen heating is used, the enclosure interior air temperature should be
kept > 0°C.
The combination of interior heating and platen heating must insure that the interior platen
surface remains greater than the dew point of the enclosure air mass.
The M3xx senor head should not be sealed and should instead remain exposed to the
interior air mass of the enclosure.
The enclosure and/or placement of the enclosure should provide shading features for the
platen area to prevent direct sun exposure.