AccuMac AM1850 Specifications

AM1850/1860 Metal-Sheath SPRTs

HIGHLIGHTS

OVERVIEW

 Metal sheathed
 Great reference thermometer for

dry block calibrators

 Temperature range: -200 °C to

Standard Platinum Resistance Thermometers (SPRTs) are common used to interpolate
temperature in the range from -189.3442 °C to 660.323 °C on the International Temperature
Scale of 1990 (ITS-90). They are widely used as standard or reference thermometers to
calibrate other thermometers and to measure temperature precisely in primary and
secondary laboratories. AM1850 and AM1860 SPRTs are the crown jewels of AccuMac
temperature probes. It takes decades of our scientific expertise and original craftsmanship to
create these world class products. They feature a very low drift rate.

To improve the durability of the SPRT, Inconel 600 replaces quartz glass as sheath material of
the thermometer. A special capsule is adopted to protect the platinum sensor wire from
contamination introduced by metal sheath at high temperature. All parts used in the
thermometer are completely cleaned and treated at high temperature before assembly. The
gas mixture filled in the thermometer is well controlled to reduce oxidation effect as low as
possible. Every SPRT is fully tested for stability after manufactured. This world class probe
meets ITS-90 criteria of standard thermometer fully with a very competitive pricing.

670 °C

AM1850 has a temperature range from -200 °C to 500 °C. AM1860 covers range from -200 °C
to 670 °C. They are widely used as reference thermometer at drywell block calibrator and
temperature bath.

Address: 90 N William Dillard Drive C-107, Gilbert, AZ 85233 For Technical Help: [e-mail]
Phone: [phone] For Sales: [e-mail]

© 2017 Accumac Corporation, All Rights Reserved www.accumac.com

AM1850/1860 Metal-Sheath SPRTs

TM

SPECIFICATIONS

Temperature Range 1850: -200 °C to 500 °C

1860: -200 °C to 670 °C

R

Nominal 25 Ω or nominal 100 Ω

tpw

Resistance Ratio W(Ga)>=1.11807

W(Hg)<=0.844235

Drift at 0.01 °C* 1850 <0.002 °C after 100 hours at 500°C,

<0.008 °C/year typical
1860 <0.003 °C after 100 hours at 661°C,
<0.01 °C/year typical

Repeatability ±0.0015 °C
Thermal Shock ±0.0015 °C after 10 times thermal cycles from minimum to

maximum temperatures

Self-heating 0.0015 °C at 1 mA current
Measurement Current 1 mA
Sensor Length 42 mm
Insulation Resistance >1000 MΩ at room temperature
Sheath Material Inconel
Dimension 1850: 6.35 mm (OD) X 480 mm (L)

1860: 6.35 mm (OD) X 500 mm (L)

External Leads Insulated copper wire, 4 leads, 2.5 meters
Termination Gold-plated Spade
Handle Dimension 21 mm (OD) X 80 mm (L)
Optional Calibration NVLAP/ISO17025 accredited calibration and data available

per request

*Long-term drift rate is for reference only. It could be affected by such facts as handling, application, and maintenance, etc.

ACCESSORIES

Model Description

9002 Wooden Carrying Case included

Address: 90 N William Dillard Drive C-107, Gilbert, AZ 85233 For Technical Help: [e-mail]
Phone: [phone] For Sales: [e-mail]

© 2017 Accumac Corporation, All Rights Reserved www.accumac.com