Omega Products OS951 User Manual

J-35

Common Surface OS590

Conventional IR “Point and Shoot”

Temperature Series IR Guns and Probes Including Conventional Contact Probes,

Reason # Measurement Errors Thermometers Laser-Aimed Units Thermocouples, RTDs, Thermistors

1 Preset Emissivity Errors No effect Very sensitive No effect 2 Emissivity Shift Errors No effect Very sensitive No effect 3 User Adjustment Errors No effect Very sensitive No effect 4 Background Errors No effect Very sensitive No effect 5 Contact Errors No effect No effect Very sensitive 6 Friction Heating Errors No effect No effect Very sensitive 7 Heat Sinking Errors No effect No effect Very sensitive 8 Time-Based Errors No effect No effect Very sensitive

OS950 Series infrared scanners from OMEGA

provide the highest

accuracy available anywhere! They are very different from

conventional temperature measuring devices. These scanners are the only infrared instruments with certified NIST-traceable accuracy on real surfaces of unknown emissivity, and they are free of the contact errors and heat errors of contact devices. Traceable accuracy applies to surfaces with an emissivity of 0.8 or higher.

Digital Infrared Scanners

High Accuracy, Certified NISTTraceability

Recessed cone traps all emitted surface radiation and blocks out any radiation from environment.

Only a thin lip of material actually contacts the target, thus minimizing heat transfer.

Actual measurement area is in the center, well away from the area contacted by the edge of the cone.

Reflective cone automatically corrects for emissivity variations by creating an actual blackbody at the precise location of measurement.

Figure 1. Unique Automatic Emissivity Compensation System (AECS) produces accurate temperatures everywhere the infrared probe is placed by creating its own blackbody.

OS951 with integral sensing head, $359, shown smaller than actual size.

8 Reasons the OS950 Handheld Infrared Scanners from OMEGA are Superior to Conventional Devices:

Actual Emissivity

Conventional IR Assumption

Temperature

550 500 450 400 350 300

1 0.8 0.6 0.4 0.2 0

290

200

150

Non-metals and Oxides

Emissivity

Clean Metals

°F

Effect of Emissivity on Temperature Reading for a

260°C (500°F) Target in 21°C (70°F) Ambient

Conventional infrared

Figure 2. The OS950 Series is accurate over a wide emissivity range, sufficient to include all non-metals. If a marker (or any other non-metal coating) is used, the OS950 Series is accurate on clean metals as well. Conventional infrared devices are very inaccurate on these surfaces.

°C

OS950 Series w/o marker

OS950 Series using marker

OS950 Series

Starts at

359

1. No Emissivity Errors

The true emissivity of a surface can never be accurately determined by conventional infrared devices. Without OMEGA’s automatic emissivity compensation system (see Figure 1 above), infrared devices with a preset emissivity setting can only display an approximate temperature over their entire temperature range.

The accuracy specifications given by most manufacturers are only for a “blackbody” calibration and do not hold outside laboratory conditions. Blackbody calibrations totally ignore emissivity shifts, ambient change effects on the target, and

other phenomena. Only OMEGA’s OS950 Series is unaffected by these distortions (see Figure 2 above).

2. No Emissivity Shift Errors

Even if an infrared “gun” is set to the correct emissivity to read a surface accurately at a particular temperature, it may not read the same target correctly at other temperatures. The emissivity of virtually all surfaces changes with temperature. For non-metals, the average change in emissivity is approximately

-2% per 100°F target temperature change (-3% per 100°C).

The sensing surface area of the OS950 scanners is reflective to correct for emissivity variations.

Covered by U.S. and

International patents and

pending applications.

PATENTED

No points

Extended Warranty

Program

J-36

Specifications

Temperature Range:

OS951/2: -45 to 287°C (-50 to 550°F) OS953/4: -18 to 540°C (0 to 1000°F) OS955: 86 to 653°C (186 to 1207°F) OS956: 86 to 871°C (186 to 1600°F)

Emissivity Adjustment:

Automatic emissivity compensation system (best for emissivity above 0.8)

Accuracy: ±1% of reading or 2°C Linearity Error (% of Reading):

OS951/2: 1% OS953/4/5/6: 3%

Emissivity Error: -1% maximum of

difference between target temperature and instrument temperature when touching, for emissivity of 0.8 to 1.0

Repeatability: 0.1°C (-0.1°F) Resolution: 0.1°C (0.1°F) Response Time: Approx 0.1 s Field of View: 1:1 (approx 53°) Minimum Spot Size:

Approx 6.4 mm (0.25")

Spectral Response: 2 to 20 microns Digital Output: RS232

(optional on all units)

°C/°F Conversion: Yes Operating Temperature Range:

0 to 50°C (32 to 122°F)

Power: 9V battery (included) Battery Life: Approx 5000 readings Dimensions: 165 H x 51 W x 25 mm D

(6.5 x 2 x 1")

Weight: 198 g (7 oz)

High Accuracy = High Speed in Your Process!

To Order

(Specify Model Number)

Model No. Price Range Description OS951 $359 -45 to 287°C (-50 to 550°F) Handheld IR scanner with integral sensor

OS952 619 -45 to 287°C (-50 to 550°F) Handheld IR scanner with integral sensor OS953 879 -18 to 540°C (0 to 1000°F) Handheld IR scanner with integral sensor OS954 1125 -18 to 540°C (0 to 1000°F) Handheld IR scanner with integral sensor Options Price Description

-RS232 $50 RS232 digital output with 1.8 m (6') cable and 9-pin female connector

3. No User Adjustment Errors

A setting of emissivity = 0.9 on an infrared “gun” from one manufacturer will not necessarily match that on a different gun from another manufacturer. No industrywide standards exist for the precise use of emissivity in measurement. Therefore, quality-assurance programs should not rely on any instrument that allows users to alter the instrument settings.

4. No Background Reflection Errors

Even if the emissivity were constant at all temperatures (see reason 2, on page J-35), errors could still occur depending on changes in ambient temperatures. For example, with emissivity = 0.9, ambient reflections account for 10% of the signal that the infrared gun will detect. If the ambient temperature changes, the infrared gun will display a different target temperature, even if the target remains at the same temperature (see Figure 3 below).

5. No Contact Errors

Thermocouples, RTDs, thermistors, and other contact devices only measure their own temperature, not the surface temperature. When using such devices, one must ensure that the probes are brought to the same temperature as the surface.

6. No Friction Heating Errors

For moving surfaces, a contact probe is prone to friction heating errors. The size of the error depends on the roughness of the surface, the speed, the coating on the probe, and so on. It is impossible to control all the variables.

7. No Heat Sinking Errors

For most non-metals, heat sinking errors can be quite large. The metal leads of contact probes conduct heat faster than the target material can replace it, resulting in fairly sizable errors. In general, the less thermally conductive the target material, the larger the heat sinking error with a contact probe.

8. No Time-Based Errors

Contact temperature probes are slow. The temperature of a target can change more quickly than most probes can measure, causing errors in real-time measurement. (see Figure 4 below)

OMEGACARESMextended warranty program is available for models shown on this page. Ask your sales representative for full details when placing an order. OMEGACARE

covers parts, labor and equivalent loaners.

0 20 40 60 80 100 120

Ambient T (°F)

Effect of Ambient Temperature (T) on Reading

for 38°C (100°F) Target with 0.8 Emissivity

4 16 27 38

110

106

102

Tar get T (°C)

Figure 3. OS950 Series scanners remain accurate even if the

ambient temperature varies, while conventional infrared devices are considerably inaccurate.

OS950 Series

Conventional infrared

OS953 with integral sensing head, $879, shown smaller than actual size.

Comes complete with operator’s manual, 9 V battery and NIST certificate. Ordering Examples: OS951-RS232, handheld infrared scanner with integral sensor,

-45 to 287°C (-50 to 550°F) range, and RS232 communications option, $359 + 50 = $409. OCW-2, OMEGACARE

extends standard 2-year warranty to a total of 4 years ($73),

409 + 73 = $482.

OS952, handheld infrared scanner with integral sensor, -45 to 287°C (-50 to 550°F) range, $619.

OS952 with remote sensing head, $619, shown smaller than actual size.

0.001 0.01 0.1 1 10 100 1000

260 200 150 90

Time Comparison Between OS950 Series and Contact

Thermocouple for Measuring a 260°C (500°F) Surface

500 400 300 200 100

°C

Contact probes

OS950 Series

°F

Contact error

Time from Start of Measurement (s)

Figure 4. OS950 Series scanners measure surface

temperature in a fraction of a second, while contact probes (thermocouples, RTDs, thermistors, etc.) require several minutes to achieve equilibrium. In addition, contact probes always have a residual error because of imperfect heat transfer from the surface to the probe.