9190A Ultra-Cool Field Metrology Well





9190A Ultra-Cool Field Metrology Well

Great for clean room environments

Calibration baths are the most stable and uniform temperature sources available, but they aren’t a good fit for clean rooms. The size of a bath limits its portability, and bath fluids can easily spill and give off vapors. The 9190A Ultra-Cool Field Metrology Well is a great alternative. Its wide temperature range brackets the coldest and highest temperature ranges required for pharmaceutical, biomedical and food processing applications. The 9190A is small and lightweight, making it easy to transport. And since it does not use heat transfer fluids, clean rooms stay clean. The 9190A cooling and heating times are faster than a calibration bath—that means calibration work gets done more quickly.

An accurate temperature source is critical for dependable process measurements

Unreliable process measurements can have a damaging impact on business, leading to poor product quality, recalls, fines, waste, and lost profits. Ultimately, measurements are only as good as the temperature sources used to calibrate the measurement equipment. The 9190A Ultra-Cool Field Metrology Well incorporates the best technology and design expertise gained from decades of dry-block development experience. The 9190A conforms with EURAMET cg-13 guidelines for best measurement practices for temperature block calibrators. As a result, you can be assured that the 9190A specifications for accuracy, stability, axial (vertical) uniformity, radial (well-to-well) uniformity, loading, and hysteresis have been thoroughly and carefully defined and tested. With a 9190A Ultra-Cool Field Metrology Well, you can be confident you’re using the most accurate and stable ultra-cool dry-block calibrator available. And that will have a positive impact on your business.


Ultra-cool dry-block calibrator with best-in-class stability

The Fluke Calibration 9190A Ultra-Cool Field Metrology Well is the most accurate and stable, cold temperature dry-block on the market. It’s ideal for applications that demand strict quality control and regulatory process compliance. These applications include on-location validation and calibration of RTDs, thermocouples, thermometers, and sensors used with process control equipment such as medical freezers, laboratory refrigerators, cold rooms, blood banks, sterilizers (autoclaves), and freeze dryers.

Wide temperature range

–95 °C to 140 °C

Excellent accuracy

Accuracy using built-in reference thermometer readout:  ± 0.05 °C full range

Display accuracy:  ± 0.2 °C full range

Best-in-class stability

± 0.015 °C full range

Fast cooling time

23 °C to –90 °C:  80 minutes

23 °C to –95 °C:  90 minutes

140 °C to 23 °C:  60 minutes


Weighs only 16 kg (35 lbs)

Built-in front and back handles for easy two-handed carry

Best measurement practices

Conforms with EURAMET cg-13 guidance on measurement practices for temperature calibrators


Basunit specifications
Temperature range at 23 °C –95 °C to 140 °C (–139 °F to 284 °F)
Display  accuracy ± 0.2 °C full range
Accuracy with  external reference[3] ± 0.05 °C full range
Stability ± 0.015 °C full range
Axial uniformity at 40 mm (1.6  in) ± 0.05 °C full range
Radial gradient ±0.01 °C full range
Loading effect (with a 6.35  mm reference probe  and three  6.35  mm probes)
± 0.006 °C full range
(versus display  with one 6.35  mm probe)
± 0.25 °C at –95 °C
± 0.10 °C at 140 °C
Operating conditions 0 °C to 35 °C, 0 % to 90 %
RH (non-condensing) < 2000 m altitude
Environmental conditions for all specifications except temperature range 13 °C to 33 °C
Immersion (well)  depth 160  mm (6.3 in)
Well diameter 30 mm (1.18 in)
Heating time[1] –95 °C to 140 °C  : 40 min
Cooling  time[1] 23 °C to –90 °C  : 80 min
23 °C to –95 °C  : 90 min
140 °C to 23 °C  : 60 min
Stabilization time[2] 15 min
Resolution 0.01  °
Display LCD, °C or °F user selectable
Size (H x W x D) 380 mm x 205 mm x 480 mm (14.9 in x 8.0 in x 18.8 in)
Weight 16 kg (35 lb)
Power requirements 100 V to 115 V (± 10 %) 50/60 Hz, 575 W
200 V to 230 V (± 10 %) 50/60 Hz, 575 W
System fuse  ratings 115 V  : 6.3 A T 250 V
230 V  : 3.15  A T 250 V
4–20 mA Fuse  (-P model only) 50 mA F 250 V
Computer interface RS-232 interface
Safety IEC 61010-1, Installation Category II, Pollution degree 2
Electromagnetic environment IEC 61326-1  : Basic
Refrigerants R32 (Difluoromethane)
< 20 g, ASHRAE safety group A2L
R704 (Helium)
< 20 g, ASHRAE safety group A1
Built-in reference thermometer readout accuracy (4-wire reference probe)[3] ± 0.010 °C at –95 °C
± 0.013 °C at –25 °C
± 0.015 °C at 0 °C
± 0.020 °C at 50 °C
± 0.025 °C at 140 °C
Reference resistance range 0 Ω to 400 Ω
Reference resistance accuracy[4] 0 Ω to 42 Ω  : ± 0.0025 Ω
42 Ω to 400  Ω  : ± 60 ppm of reading
Reference characterizations ITS-90, CVD, IEC-751, resistance
Reference measurement capability 4 wire
Reference probe connection 6-pin din with INFO-CON technology
Built-in RTD thermometer readout accuracy NI-120  : ± 0.015 °C at 0 °C
PT-100 (385)  : ± 0.02 °C at 0 °C
PT-100 (3926)  :  ± 0.02 °C at 0 °C
PT-100 (JIS)  : ± 0.02 °C at 0 °C
RTD resistance range 0 Ω to 400 Ω
Resistance accuracy[4] 0 Ω to 25 Ω  : ± 0.002 Ω
25 Ω to 400 Ω  : ± 80 ppm of reading
RTD characterizations PT-100 (385), (JIS), (3926), NI-120, resistance
RTD measurement capability 2-wire, 3-wire, and 4-wire RTD with jumpers  only
RTD connection 4-terminal input
Built-in TC thermometer readout accuracy[5] Type J  : ± 0.70 °C at 140 °C
Type K  : ± 0.75 °C at 140 °C
Type T  : ± 0.60 °C at 140 °C
Type E  : ± 0.60 °C at 140 °C
Type R  : ± 1.60  °C at 140  °C
Type S  : ± 1.60  °C at 140  °C
Type M  : ± 0.65  °C at 140  °C
Type L  : ± 0.65  °C at 140  °C
Type U  : ± 0.70 °C at 140 °C
Type N  : ± 0.75 °C at 140 °C
Type C  : ± 1.00 °C at 140 °C
TC millivolt range –10  mV to 100 mV
Voltage accuracy 0.025 % of reading +0.01 mV
Internal cold  junction compensation accuracy ± 0.35 °C (ambient of 13 °C to 33 °C)
TC connection Miniature connectors (ASTM E1684)
Built-in mA readout accuracy 0.02  % of reading + 0.002 mA
mA range Cal 4-22 mA, Spec 4-24 mA
mA connection 2 terminal  input
Loop power function 24 V dc loop power
Built-in electronics temperature coefficient
(0 °C to 13 °C, 33 °C to 50 °C)
± 0.005 % of range  per °C

Notes  :
[1]   For ambient temperature of 23 °C.
[2]   Time from when the SETPOINT is reached to when the unit is with in stability  specification.
[3]   The temperature range  may be limited by the reference probe  connected to the readout.
The built-in reference accuracy  does not include  the sensor  probe  accuracy.  It does not include  the probe  uncertainty or probe  characterization errors.
[4]   Measurement accuracy  specifications apply within  the operating range  and assume 4 wires  for PRTs. With 3-wire RTDs add 0.05  Ωto the measurement accuracy  plus the maximum possible  difference between the resistances of the lead wires.
[5]   The thermocouple input readout is sensitive to EM fields in the frequency range  of 500  MHz to 700  MHz.

Models and Accessories

Model Name Description
9190A-X  Ultra-Cool Field Metrology Well,  –95 °C to 140 °C, w/9190-INSX

“X” in the model number to be replaced with A, B, C, D, E, and F as appropriate for the desired insert.

9190A-X-P Ultra-Cool Field Metrology Well, –95 °C to 140 °C, w/9190-INSX, with Process Electronics

“X” in the model number to be replaced with A, B, C, D, E, and F as appropriate for the desired insert.

Accessories common to all models  :

Accessory Description
9190-INSA Insert “A” 9190A, imperial miscellaneous holes
9190-INSB Insert “B” 9190A, imperial comparison holes 
9190-INSC Insert “C” 9190A, 0.25 inch holes 
9190-INSD Insert “D” 9190A, metric comparison holes 
9190-INSE Insert “E” 9190A, metric miscellaneous holes with 0.25 inch hole
9190-INSF Insert “F” 9190A, metric comparison miscellaneous holes with 0.25 inch hole 
9190-INSZ Insert “Z” 9190, blank
9190-INSY1 Insert “Y1” 9190A, custom insert with blank insulator. 
9190-INSY2 Insert “Y2” 9190A, custom insert with custom insulator.

Knowledge and Information

Product Manuals


Application Notes

Data Sheets

Papers / Articles

Press Releases




9190A Ultra-Cool Field Metrology Well Video Introduction