Pajari Instruments Ltd., since 1945




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   Tropari SDP - Introduction Tropari SDP Brochure  Click here for a printable version of this page.

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  Tropari Instrument  

The Tropari is a single-shot, micro-mechanical borehole surveying instrument operated by a timing device.

Borehole direction is measured from the earth's magnetic field.

The Tropari provides both direction and inclination which can be used to define the attitude of the borehole at the survey depth.

Regular surveys at intervals as the borehole progresses will allow a plot of the borehole to be drawn from the data.


The Tropari is easy to use and maximizes profits by minimizing capital and operational costs.

The Basic Survey Train Consists of:

  • PDSI / Tropari Container,

  • 6m (20 ft) Nonmagnetic Rods,

  • Impact Foot,

  • and Connector at Top.


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  • Excellent value

  • Ideal for continuous or periodic service

  • No need for specialized training

  • Wide operating temperature range

  • Up-holes, down-holes, horizontal or inclined holes of any angle can be surveyed without modification.

  • The azimuth and inclination can be read as soon as the TROPARI is retrieved from the hole - and the readings remain fixed until the next survey.

  • No films, batteries, hazardous liquids or other operating expendables are required.

  • Single shot surveying at the bottom as the hole progresses avoids errors caused by "magnetic cake" on the bore walls -- and identifies hole deviations in time for efficient decisions.

  • The choice of lowering accessories is extensive so that you can customize your surveying train to suit your needs.

Application hardware for the Tropari SDP can be customized to suit special needs and large hole sizes. We take pride in our time proven ability to provide customers with solutions for their special hardware needs.

Please note that the Tropari SDP is a magnetic azimuth instrument. It does not measure azimuth direction while inside holes that are cased in steel or while inside steel drill rods. Through the bit surveying in wireline drilling applications is performed by using several non-magnetic aluminum rods to extend the instrument beyond the magnetic influence of the drill rods.

The Tropari SDP instrument is CE approved. Pajari Instruments Ltd is committed to the reliability and longevity of its products and service. A 1 year Warranty is standard on the Tropari instrument.

For further details and full product specifications please download the Tropari SDP brochure.


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Fully gimbaled with jewel bearings for all moving parts utilized in survey functions. Positive engagement inclinometer (for inclination) and compass (for direction) synchronized to a Swiss 17 jewel timing mechanism.

Corrosion Protection:
Gold plating and use of non-corrodible or corrosion resistant alloys where possible.

Quality Control:
Registered to ISO 9001-2000 International Standards.

Inclination & Azimuth:
Inclination scale is a protractor with positive engagement teeth at 1 ° intervals giving +/-0.5 ° accuracy. Compass has 1° divisions and is readable and accurate to +/-0.5 °. Factory calibrations are to these values.

Time Setting Range:
Model 201 - 0 to 90 minutes elapsed time (standard), less 10 minutes for locking cycle.
Model 211 - 0 to 150 minutes elapsed time (special), less 10 minutes for locking cycle.

EX-AX Models - outside dimension 33.2 mm (1.310 inches).
SDP Model - outside dimension 31.7 mm (1.248 inches).

Minimum Borehole Sizes:
EX-AX Model - 37 mm (1.455 inches) for adequate pressure and use protection.
SDP Model - 35.6 mm (1.399 inches) for adequate pressure and use protection.

Temperature Range:
-20 °to +160 ° C without modification. For holes over 5 cm (2 inches), thermal protection can be provided by insulated containers to 250 °C. Service to -50 °C can be provided with a low temperature oil change.

No limit on inclination without modification. Azimuth cannot be obtained in steel casing or within drill rods. TROPARI has to pass min. 6 m (20 ft.) past bit, or be open hole to give true azimuth without magnetic interference.

Instrument alone 90 gm (3.2 oz), with aluminum instrument box 714 gm (1 lb. 9 oz).
Shipping weight 1.5 kg (3.0 lb). Accessories vary in weight.

Customer Information Required:
Country in which the instrument is going to be used so that the compass can be balanced for the proper magnetic latitude. Drilling equipment being used so that the appropriate accessories can be selected.

Surveys in Open Holes:
Lowering can be by cable if inclination is >45 °; any inclination if by rod.
Minimum borehole is 36 mm or EW - with no maximum.

Surveys Through the Bit & Wireline:
BQ minimum at 36.5 mm (1.44 inches) internal bit diameter. Standard procedure is to raise the rods 7.6 m (25 feet) from the bottom to allow the survey train to pass through the bit beyond the magnetic influence of the rods. Can be pumped in. No maximum.

Surveys Through the Rod Only:
If the bit is removed and the rods inserted into the borehole, the instrument train can be pumped past the end of the rods in shallow and up-holes in AQTK and ATW surveying.

Services Available:
Sales, rentals*, lease to own*, service, repair, calibration, technical support, contract surveying, custom instrument and accessory design and manufacture.

*some conditions may apply


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  Tropari Online Quotation Request Form  
  The Basic Tropari Survey Train  


Tropari Survey Train


The diagram above illustrates the structure of the survey train. 

  • The connector attaches the survey train to the lowering device.

  • The aluminum rods separate the instrument from the magnetic influence of the steel lowering device or drill rods.

  • The instrument container is what holds the Tropari.

  • The plastic impact foot and the 60cm - 2' aluminum rod are part of the impact protection system.

The aluminum rods are available in two outside diameters: "E" - 35mm (1.375") and "A" - 41.3mm (1.625").

The instrument container is available in two sizes: "BQ" size for smaller diameter applications and the standard  "A" size for larger diameter applications.


Centralizers are required for larger diameter holes and are placed at connection 1 for rod lowering and wireline surveying, and at both connections 1 and 2 for cable lowering and open hole surveying.

  Information and questions specific to your surveying method will be found below.  

To help us provide you with an accurate price quotation of your Tropari surveying requirements, please complete the information below, then press the submit button found at the bottom of the page.

* denotes required fields

Contact information:  
Name: *
E mail Address: *
Telephone Number:
Fax Number:

Shipping Address (required to quote freight charges)




State / Province


Zip / Postal Code

Please choose the Tropari Survey method you require.

Wireline     Open Hole     

Survey Direction(s)? 

Up-hole   Down-hole   Horizontal

Tropari Wireline Surveying
Using the "Wireline" surveying method, the drill rods are lifted from the bottom of the hole 10 meters (30 feet) to allow the "survey train" to pass through the drill bit up to a connector.

Core Size(s)?

AQ   BQ   NQ  HQ   PQ     Other

Choose your connector, there are two types of connectors available:
Inner tub subs - Click to make picture large

The inner tube sub threads onto the inner tube (core barrel) when the core lifter casing is removed. This is the most versatile connector as it can be used in up-hole, down-hole and horizontal drilling without modification.

inner tube sub
Landing Couplings - Click to make picture large

The landing coupling is a "pin" to "pin" oversize coupling which will not go through the bit. With the proper adapters, it can be used with a cable swivel or spearhead. This method can only be used in down-holes steeper than 40.

landing coupling     with spearhead     with cable swivel

Wireline sizes BQ and larger can be surveyed through the bit. AQTK can be surveyed through the rod by removing the bit and using an AQTK inner tube sub.

Tropari Open Hole Surveying
Holes drilled with conventional (non-wireline) core barrels, non-coring rotary, percussion, cable-tool or reversed circulation equipment must be surveyed "open hole". The survey train can be placed at the survey depth by DRILL ROD in any borehole or by CABLE in holes that are steeper than 45.

Actual Hole Diameter? (to determine proper size of centralizers )

 mm   inches

Required connectors for Open Hole Cable Lowering:
Cable Swivel - Click on picture to make large The cable swivel comes with a 1" 16 tpi pin thread.

Cable Swivel

Cable Adapters - Click to make picture large.



Our cable swivel adapter comes with  a 1" 16 tpi box thread to accept the cable swivel. The pin thread matches the "E" and "A" thread we use on our non-magnetic aluminum rods.

Cable Swivel Adapter

Centralizers for survey train stability in the hole:

One or two centralizers may be required, depending on your hole size and surveying method, to stabilize the survey train in the hole. These centralizers are available in standard wireline sizes, as well as variable coupling sizes custom manufactured to your borehole requirements.

Centralizers - Click on picture to make large. Variable Disc Centralizers - Click on picture to make large. Variable Sleeve Centralizers - Click on picture to make large.
Wireline Centralizers Variable Disc Coupling

Variable Sleeve Coupling

In "open hole" surveys the "rule of thumb" is to make the centralizers 13mm or 1/2" smaller in diameter than the actual hole diameter. This size can change based on the rock and soil conditions in the hole. 

Other Information

Hole Length? 

 meters   feet

Is the hole filled with water?

yes   no

Is the hole you will be surveying "cased"? 

Yes   No

If Yes, with what material?

Steel   Plastic  Other

If Yes, what is the inside diameter (ID) of the "casing"?

 mm   inches


Pajari Instruments Ltd. 2015

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