DeFelsko PosiTector SPG

The spring pressure is slightly greater than the SPG TS to allow adequate seating of the tip in the profile. Keep in mind that no standards exist for such a method, so we designed the pressure based on our internal tests.

All PosiTector SPG probes including the SPG TS are traceable to PTB

No. Our instruments are designed for simple operation, feature easy-to-use menus, both full and quick instruction manuals, and helpful videos. In lieu of demonstration models, we provide unlimited technical support via telephone and/or email, and a limited 30-day money back guarantee

The PosiTector SHD arrives fully calibrated and ready to measure. A Long-Form Certificate of Calibration traceable to NIST or PTB is included, which documents actual readings taken by your instrument at our calibration laboratory on standards traceable to a national metrology institute. Beware of ‘Certificates’ or ‘Certificates of Conformance’ offered by competitors. These typically do not include actual instrument readings, and are often insufficient to meet common quality requirements.

Gage accuracy and correct operation can be verified using the included metal shim and glass zero plate.

To measure accurately, the PosiTector SPG’s probe foot must contact the surface over its entire area. On tightly curved surfaces, the edges of the probe do not sit on the surface, skewing the readings.

Our PosiTector SPG instruments conform to Method B as described by ASTM D 4417 "Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel". The entirety of ASTM D 4417 specifically references flat, blasted steel surfaces. As such, any depth micrometer instrument used to measure the surface profile of a curved, blasted steel surface does not conform to ASTM D 4417.

Replica tape is ideal for recording the blast profile of curved surfaces, and DeFelsko recommends the PosiTector RTR Replica Tape Reader instrument as a reliable measurement alternative.

Yes! While primarily used to measure blasted steel, the PosiTector SPG can be used for many applications. The PosiTector SPG TS and PosiTector SPG CS also feature an extended range and larger radius probe tip to suit a wide range of applications:

1. The PosiTector SPG CS will quickly and accurately measure the surface profile of textured coatings.
2. The PosiTector SPG TS will quickly and accurately measure the surface profile of concrete.

The PosiTector SPG uses a durable tungsten carbide tip for long life and continuous accuracy. If required, SPG probe tips can be replaced by the gage operator

• The 60° tip complies with most test standards including ASTM D 4417 B.
• 30° tips are available for conformance to Australian standard AS 3994.5-C.

No. The PosiTector SPG is a depth-micrometer instrument which quickly and accurately measures and records peak-to-valley surface profile heights on a blasted steel surface.

Like other instruments of this type, the PosiTector SPG is not dragged across a blasted surface: the gage operator takes an individual reading in one location on a surface, lifts and places the gage on another location on the surface for another individual reading, and so on.

No. Pit gages are a general category of instruments used to measure pits and other surface variations. The PosiTector SPG is specifically designed to measure and record peak-to-valley surface profile heights on a blasted steel surface

Both instruments conform to ASTM D 4417 "Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel".

The PosiTector SPG conforms to Method B of ASTM D 4417. The PosiTector SPG measures quickly, and has no per-test cost. It keeps a digital record of each measurement, is less operator dependent, as no burnishing of replica tape is required. It also has a greater range than replica tape.

The PosiTector RTR conforms to Method C of ASTM D 4417. It is used together with Testex Replica tape, a widely used and respected method to measure surface profile. It has the ability to measure on curved surfaces, and gives the user the option to retain the replica tape; a physical replica of the tested surface.

PosiTector probes include a Certificate of Calibration with no expiry or end date. They have no shelf life, therefore the length of time in the field is not a good indicator for recalibration intervals. Many organizations with quality programs and recertification programs require annual recalibrations, and this is a good starting point for most users. DeFelsko recommends that customers establish calibration intervals based upon their own experience and work environment. Based on our product knowledge, data and customer feedback, a one year calibration interval from the date the instrument was placed in service is a good starting point

The PosiTector SPG OS is designed with a self-leveling probe foot to ensure perpendicularity to the part being measured. The finger grip sleeve needs to have a loose fit in order for self-leveling to work.

The Large V-groove Adaptor offers enhanced stability on 30 – 45 cm (12 – 18") OD pipes and helps with proper positioning and measuring technique. The adaptor should not be used on pipes greater than 46 cm (18”).

On flat surfaces, the PosiTector SPG, SPG S, and SPG OS probes will measure similarly. However, measurements taken by the PosiTector SPG OS (or any depth micrometer surface profile instrument) on rounded surfaces should only be compared with measurements taken on surfaces with a similar radius. On flat surfaces, the probe foot contacts the substrate over its entire area, while on curved surfaces the probe foot contacts an increasingly smaller area as the radius decreases. This may cause a slight decrease in the reported peak-to-valley surface profile height, since the probe foot sits on fewer peaks as the contact area decreases.