Worldwide Source for the Leading Technologies in Process Instrumentation and Controls
I.R.S., Incorporated - a MicroMod Company
3 Townline Cir Ste 4, Rochester, New York 14623
Phone 1 (585) 321-9261 - Fax 1 (585) 321-9291

E-mail Us -

Formerly Weed Instrument

Industrial RTD Temperature Products

Ultra manufactures a comprehensive line of both RTD and Thermocouple-based temperature sensors. These products include bare elements suitable for incorporation into OEM products, standard probe-type sensors, field cuttable sensors, sanitary assembly sensors, and HVAC sensors. Standard products also feature fast delivery times, 48 hours in most cases. Accessories such as thermowells and explosion-proof heads are also available. 

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General Purpose RTDs  by Ultra


Designed for a wide range of applications where a simple mounting scheme is required.


Model 101 is a Straight Sheath temperature sensor.
Refer to Model 201 if welded fitting is required.
Refer to 300 Series if spring loading is required
       301 & 304 - Spring Loaded Sensor with Explosion Proof Housing
       302 & 303 - Spring Loaded Sensor w/o Transmitter for General Purpose Housing
       305 Series - Spring Loaded with 1/2" NPT Hex Nipple
       305 Ex-d Series - ATEX-Approved, Flame-Proof Temperature Sensor
       305 Ex-ia Series - ATEX Intrinsically-Safe Temperature Sensor Assembly
       312 Series - Spring Loaded Sensor w/ 1/2" NPT Hex Nipple

Model 102 is a Copper Tip Sensitive temperature sensor.
Refer to Model 303 or 304 if spring loading is required

Model 103 is a Reduced Tip/Fast Response temperature sensor.
Refer to Model 203 if welded fitting is required

Model 110
Field Cuttable RTD
by Ultra

Designed for applications where a threaded male fitting is required for mounting in tanks, stacks, pressure vessels. Stocking “cuttables” can reduce inventory and down time as the 110 can be easily cut to the required length in the field and a fitting can be installed in a matter of minutes

Model 110 is designed to be used with optional connector or spring-loaded fitting



Model 451
Direct Immersion Sanitary RTD
by Ultra

Designed for temperature measurement applications in food, beverage, pharmaceutical and other applications where sensor corrosion and product contamination are critical.

Model 451 combines a polished RTD probe with a choice of sanitary cap fittings and connection heads. The probe sheath and sanitary cap are welded to the lagging extension.

Surfaces are available ranging from 63 to 8 Ra.
Choice of sanitary fittings
Reduced-tip option
Choice of connection heads including a special epoxy
coated version for protection during caustic washdown.
No. 4 finish meets 3A standards. (Min.)

451 Series Data sheet

Model 452
Spring Loaded Sanitary Temperature Sensor
by Ultra

Ultra, has expanded on its already successful model 451. The model 452 is designed to be used in applications where spring loading is desired for fast temperature response when used in a sanitary thermowell.
Model 452 features no exposed threads where bacterial growth or contamination can be a problem. Multiple configurations are possible, including dual sensor versions for back up and comparative measurement, options for protection heads and temperature transmitters locally mounted, a  In addition, multiple surface finishes can be specified on the external probe housing.
Model 452 Data Sheet


Model 461
Sanitary RTD with Removable Sensing Element
by Ultra

Incorporates a patented design which facilitates easy replacement of the temperature sensing element without the use of a standard thermowell. In addition, sensor replacement is accomplished without breaking the sanitary seal of the process.

The Model 461 combines the fast time response characteristics of a standard immersion sanitary sensor with all the advantages of a thermowell.
Removable sensing element.
Eliminates need for a thermowell.
Low replacement sensor cost.
Permits sensor removal without loss of sanitary seal.
No. 4 finish meets 3A standards
Model 461 Data sheet

Model 2543
Non-Intrusive Flow Through Sanitary Sensor
by Ultra

Designed to accura through pipes, and for use in food, beverage, pharmaceutical and other applications where sensor corrosion and product contamination are critical.

These inline RTDs are designed for direct installation. Temperature of the product is measured without flow interruption.

Model 2543 provides obstruction free measurement, with no probe to break off
All-welded construction
Choice of sanitary fittings and connection heads
Multiple pipe sizes and lengths available
Internal flow tube is polished to sanitary finish

Model 3142B
Sanitary Flush Mount Tank Temperature Sensor
by Ultra

Ultra has developed a unique flush mount,
tank temperature sensor for use in sanitary applications. The model 3142B is designed to mount flush to the wall of a tank. It is completely non-intrusive and will not interfere with any wipers or mixers in the tank.

The Model 3142B is a non-intrusive design – ideal for where mixers or wipers would interfere with typical insertion type sensors

Clean-in-place (CIP) / Steam-inplace (SIP) – dual o-ring design for sealing
316L stainless steel construction – Welding spud provided with assembly
Ideal for retrofit to existing tanks
Teflon insulation provides true process temperature measurement, by eliminating potential false reading from tank wall
Removable sensor – allows process to remain sealed during sensor replacement or calibration
Patent pending design
Model 3142B -

Model 3226A
Food Piercing Temperature Sensor
by Ultra

Ultra manufactures temperature sensors designed specifically  for use in meat processing where precise temperature measurement is required during the cooking, smoking and curing of the product.

 Available in RTD or thermocouple with separate shielding
Extruded Teflon wire insulation – Resists moisture – Increased wire strength
Heavy walled sheath construction –Resists breakage
Crimped transition with strain relief – Resists wire separation
Meets 3A sanitary finish standards


Model 3226A - Data sheet

Flexible Stick-on Surface Temperature Sensor
by Ultra

The 3304A is a flexible surface mount temperature sensor suitable for temperatures to 500 °F. The self-adhesive sensor pad makes installation simple.

Excellent surface temperature measurement is achieved using this sensor design. The model 3304A is available in both RTD’s or thermocouples to suit your current control system inputs.

The model 3304A is a temperature sensor in a self-adh  Flexible – conforms to curved surfaces
Available in RTD or thermocouple
Teflon insulated leadwire
Suitable for temperatures to 500 °F
Custom designs available
Other surface and embedded sensors are also available


Model 3304A - Data sheet
Autoclave Temperature Sensor
by Ultra

The model 3312A is designed for use in the pharmaceutical industry – specifically autoclaves where precise temperature measurement and long life is required.

These sensors are completely sealed for use inside autoclaves where pressure cycling can force moisture inside the probe.

The waterproof design extends from the sheath, through a dual crimped and sealed transition to the extruded Teflon leadwire.


Weed’s autoclave sensors can be used in industrial applications as a more cost effective option to submersible sensors. Our sensors provide long life in tough applications.

The model 3312A is a ompletely waterproof design with a 316L stainless steel sheath
Available in RTD or thermocouple versions
Extruded Teflon wire insulation – Resists moisture – Increased wire strength
Custom designs available


Model 3312A - Data sheet

Model 3332A


The Model 3332A is available in RTD or thermocouple and is designed for high vibration environments.

Water-proof / resistant design – Increased accuracy – Longer life
0.3” and smaller stainless steel sheath lengths
Multiple sheath diameters available
-50 to 260°C temperature range
Dual sensor designs available
Babbit overprotection options


Model 3332A - Data sheet

     Sensors for the Measurement of Bearing Temperatures by Ultra

Sensors designed for use in the rotating equipment and turbomachinery industries.

Ultra temperature sensors provide an excellent indication of temperature to determine when oil breakdown occurs to prevent extensive damage to machinery.

Ultras rugged designs provide for long life in tough applications.

Available in both RTD’s and thermocouples

Copper tipped RTD’s for fast time response and greater tip sensitivity

Spring loaded fittings with 50 PSI rated fluid seals

Available sheath diameters: 0.188”, 0.215” & 0.250

Cuttable design for field sizing

Electrically isolated tip design available

Wide temperature range

Cast iron, aluminum and stainless steel connection heads available

Custom OEM designs

Use an Ultra Electronics Sensor-Mate® temperature transmitter for 4-20mA output
Sensors for Bearing Temperature - Data sheet

Spring Loaded
Bayonet Fitting Temperature Sensors
by Ultra

Ultra Electronics, offers our bayonet fitting assemblies for applications where quick and easy removal and installation of a sensor is important.

Whether  for calibration purposes or normal replacement, the Ultras bayonet fitting makes the job as simple as 1, 2, 3

1 - Open the head

2 - Unplug sensor from terminal block

3 - Twist bayonet cap to remove sensor

Simply repeat those steps in reverse and you have just installed another spring loaded sensor into your process.


Spring loaded bayonet sensors - Data sheet

Easy to remove / replace sensor, with no need for tools

Spring loaded design

Pluggable Terminal Block or Transmitter can be placed in head

Use ATEX approved Flip-Top General Purpose Head (Code 19) or Screw-Top FM/CSA Explosion Proof Head (Code 3)

No risk of galled threads

Fast and simple sensor removal and installation for calibration or replacement

Use with screwed and flanged thermowells – typical ½” x ½” hex nipple installation

Specify model 101 sensor with code 505 fitting option
General purpose head with terminal block

General purpose head with termin 

Temperature Sensors
for Flow Computers and Gas Correctors
by Ultra

Ultra Electronics temperature sensors designed for use in the gas flow computer and volume corrector industries. Ultras  RTD sensors provide a highly accurate temperature measurement input for compensated flow measurements. Designed to provide for long life in tough applications.

Water-proof / resistant design – Increased accuracy – Longer life
Stainless steel armored or braided lead-wire protection
Custom designs

  • Sheath length

  • Sheath diameter 

  • Special transitions

  • Fitting options

  • Custom wire insulation

 Patented Breakable® sheath design for sizing sensor in the field


Flow Corrector Sensors - Data sheet