head- or cable type mineral insulated probes

 

"PSMSC" & "CSMSC" ranges

 

The sensing element which is generally small - 2 to 5mm diameter - is attached to a stainless steel mineral insulated cable that can be bent.

Tightness between sensing element and cable is achieved by laser welding or brazing. Connection to the readout instrument is made by a cable, a connecting head or a connector.

Temperature range
from -200°C to +500°C

Mechanical data
The materials chosen for encapsulating and for the cable as well as the type of crimping and welding are the essential elements that determine the sensor performance as far as resistance to vibrations and working conditions are concerned. 

Accuracy
1) of the sensing element
    PT100 - PT1000
    - class A: + 0.15°C + 0.002°C [t°]
    - class B: + 0.30°C + 0.005°C [t°]

2) of the sensor
Accuracy depends on the sensing element and on the type of assembly with 2, 3 or 4 wires

Response time
Indicative data for a mineral insulated RTD sensor with platinum resistance:

Time to reach x% of the temperature scale interval:

 diamètre

 63%

 90%

   2 m

 1.4

 3.3

   3 mm

 4.4

 9.8

   4 mm

 6.5

 15.4

   5 mm

 11

 25

Tests realised as per UTE C 46-202 standard, on a 1xPT100 sensor, 3 wires, temperature range: -20°C +100°C

Applicable standards
IEC 751
UTE 46202

Certifications
Mineral insulated RTD sensors may be used in potentially explosive atmospheres provided that the requirements of the 94/9/CE directive are complied with. Learn more ...

 

The most common dimensions are:

2 mm < "D" diameter > 5 mm
"L" flexible length : as per customer request
"L1" rigid tip: 30 to 60mm

 

Sensing element :


•  Platinum 100 Ohm at 0°: 1x, 2x
   2, 3 or 4 wires
 

sheath :

 
•   304, 316, 310 stainless steel

insulation :


•   standard: MgO magnesium oxide
•   high purity: pure alumina

Tip :


•  metallic tip ( SS, brass, aluminium) with annular, hexagonal or square crimping

connexion :


•  bare wires
•  connecting head
•  connector

transition :


•  undismantable junction
•  bending spring

cable :


the choice of the cable depends on:

•  the temperature to be measured
•  the required tightness
•  the operating conditions

 

Connecting diagram :

Platinum resistance 2 wires, 3 wires or 4 wires

       


Recommendations:

  • Immersed length into the measured process =  10 x diameter
  • The L length  and the type of connection  with 2, 3 or 4 wires should be determined according to the expected accuracy.
  • Ohm/4-20mA transmitters may be used with these sensors