PU series, heat flux sensors and
specials
The PU series of heat flux sensors
consists of a number of “standard” sensors with different diameters and
thicknesses.
Apart from the standard models, special
models can be manufactured on demand.
In most cases the use of the PU series
is associated with specific requirements concerning size (small or thin),
temperature (up to 250 degrees C), mounting (flexible), chemical resistance
(high) or the necessity to cover a large area.
The PU series is designed and
manufactured by TNO-Science and Industry (former TNO-TPD).
-
- Free: For a nice clear print of the original product
brochure (PDF) click here.
INTRODUCTION
The PU series standard models consist of
two categories: the PU category of 3 mm thickness and the PU-T category of 1 mm
thickness.
- Unique features of the PU series are:
-
·
record breaking
sensitivity per unit area
-
·
small sensors available
-
·
flexibility (for the PU-T
category only)
The PU series is typically applied when
one or a combination of these features is a technical necessity, for instance
measurement of fluxes from human or animal bodies, or measurements on
cylindrical surfaces. The sensor body of the PU series is made out of cast
polyurethane.
In addition the PU manufafcturing
technology is applicable whenever very large sensors need to be manufactured.
MORE INFORMATION / OPTIONS
In case the PU series specific
characteristics are not relevant, typically one should consider using the
“standard” Hukseflux models HFP01 and HFP03.
Special models can be made according to
customer specification. Typical variables to be specified are:
In particular many special designs are
made of silicone. This material choice results in high temperature, chemically
inert and more flexible sensors. The mechanical robustness however is less than
that of polyurethane. In exceptional cases epoxies are used.
PU SERIES SPECIFICATIONS
- General: see tables below
- Optional temperature measurement: Pt100
or thermocouple type K
- Optional use of silicone: temperature
range extended to 250 degrees C, improved chemical resistance. Typical minimum
thickness: 1.2 mm. Less stiff than PU. Type indication SI.
- Optional pressure resistance: to 110 bar
- Optional use of epoxy: to be resistant
against certain chemicals, however at lower flexibility. Type indication EP.
- Optional calibration: determination of
temperature dependence.
- Manufacturing: TNO Science and Industry,
former TNO-TPD
Figure 1 Dimensions of PU series, PU category of 3 mm thickness: sensitive area
(1), guard (2), cable with miniplug
(3), disconnectable miniplug (male) on sensor (4), optional
temperature sensor (5)
|
Model
|
|
PU
11
|
PU
22
|
PU
32
|
PU
43
|
PU
54
|
|
Thickness
|
mm
|
3
|
3
|
3
|
3
|
3
|
|
Overall
diameter
|
mm
|
25
|
50
|
75
|
100
|
150
|
|
Dimensions
sensitive area
|
mm2
|
10x10
|
20x20
|
25x25
|
30x30
|
50x50
|
|
Sensitivity
(nominal)
|
µV/Wm-2
|
20
|
50
|
50
|
170
|
300
|
|
Electrical
resistance
|
Ohm
|
200
|
500
|
500
|
1500
|
3000
|
|
Filling
material
|
|
PU
|
PU
|
PU
|
PU
|
PU
|
|
Temperature
range
|
°
C
|
-20
to +90
|
-20
to +90
|
-20
to +90
|
-20
to +90
|
-20
to +90
|
|
Thermal
resistance
|
m2K/W
|
0.012
|
0.012
|
0.012
|
0.012
|
0.012
|
|
Expected accuracy |
% |
|
+5%/-5% @ 20 degrees C, temperature dependence typically
0.17%/K |
|
|
Cable
connection
|
|
|
disconnectable
miniplug + cable 2m
|
|
|
Minimum
bending radius
|
mm
|
|
infinite
|
|
The PUT series
- Figure 2 Dimensions of PU series
, PU-T category of 1
mm thickness: sensitive area (1), guard (2),
fixed wires (3), minimum bending radius (4), optional temperature
sensor (5)
NOTE:
PU-T sensors can be bent, but are quite rigid.
Installation
typically requires taping.
|
Model
|
|
PU
11 T
|
PU
22 T
|
PU
32 T
|
PU
43 T
|
|
Thickness
|
mm
|
1
|
1
|
1
|
1
|
|
Overall
diameter
|
mm
|
25
|
50
|
75
|
100
|
|
Dimensions
sensitive area
|
mm2
|
Ř
15
|
Ř
30
|
Ř
30
|
Ř
55
|
|
Sensitivity
(nominal)
|
µV/Wm-2
|
8
|
30
|
30
|
150
|
|
Electrical
resistance
|
Ohm
|
400
|
1700
|
1700
|
7000
|
|
Filling
material
|
|
PU
|
PU
|
PU
|
PU
|
|
Temperature
range
|
°
C
|
-20
to +90
|
-20
to +90
|
-20
to +90
|
-20
to +90
|
|
Thermal
resistance
|
m2K/W
|
0.004
|
0.004
|
0.004
|
0.004
|
|
Expected accuracy |
% |
|
+5%/-5% @ 20 degrees C, temperature dependence
typically 0.17%/K |
|
|
Cable
connection
|
|
|
fixed
wires 2m
|
|
|
|
Minimum
bending radius
|
mm
|
15
|
25
|
40
|
50
|
-
|
