PU seriesheat flux sensors and specials
| PUseries specifications: | |
| General | see tables below |
| Optional temperature measuremente | Pt100 or thermocouple type K |
| Optional use of silicone | temperature range extended to 250 °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)
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).
A nice clear print of the original product brochure.
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
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:
- size (can be very large)
- area of sensitive part
- thickness (1 mm or higher)
- temperature / pressure range
- chemical resistance
- sensitivity
- flexibility
- heat flux range
- IP protection class
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
| 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 | 10*20 | 20*20 | 25*25 | 30*30 | 50*50 |
| Sensitivity (nominal) | µV/Wm-2 | 20 | 50 | 50 | 170 | 300 |
| Electrical resistance | Ohm | 200 | 500 | 500 | 1500 | 3000 |
| Filling material | PU | |||||
| Temperature range | °C | -20 - +90 | ||||
| Thermal resistance | m2K/W | 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 | ø 15 | ø 30 | ø 30 | ø 55 |
| Sensitivity (nominal) | µV/Wm-2 | 8 | 30 | 30 | 150 |
| Electrical resistance | Ohm | 400 | 1700 | 1700 | 7000 |
| Filling material | PU | ||||
| Temperature range | °C | -20 - +90 | |||
| Thermal resistance | m2K/W | 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 |