M/S. Girish Chandra Ghosh & G.G.S


Govt. Approved License Manufacturer / Repairer & Dealer

Govt. Approved Calibrator of Storage Tank of Petroleum, Chemical, Oil, Other Liquid Storage Tanks, Manufacturer of Weighing Machines and Complete Weighing Solution, Peg Measure. Leading Storage Tank Calibrator & Surveyor, N.D.T Inspection work, Inspection Survey & P.I Diagram in

India & Abroad

Area of Services


  • Crude oil storage tanks, product storage tanks in refineries
  • Bulk petroleum product storage in tank farms, chemical and acid storage molasses storage, bulk industrial alcohol storage.
  • Large volume storage tanks for product transfer from ship in port areas.
  • Horizontal cylindrical tanks for chemical and fuel oil storage in all process, fmcg, allied industry, railway consumer depots.
  • Underground horizontal storage frp or steel tanks in gas stations and petrol retail outlets.
  • Distilleries and breweries, who are under excise bond, require accuracy to a litre for their ms, ss tanks, brewing kettles or blenders.
  • Blending tanks with stirrers for paint industry, lube oil blending, pharmaceutical companies and other chemical mixing for exact ratio.
  • Horton spheres liquified gas storage in horizontal bullets in gas & petrochemical industries.
  • Dip-sticks of aluminium, steel or brass and dip-tapes with heavy brass weight calibrated and certified.
  • Ultrasonic thickness testing of product pipelines, ammonia pipelines, steel plates and pressure vessels.
  • Calibration of barges.

We perform our job in:

  1. Vertical floating roof tanks
  2. Vertical cylindrical roof tanks
  3. Horizontal cylindrical tanks
  4. Underground horizontal tanks
  5. Rectangular tanks
  6. Blending tanks
  7. Bullets with spherical ends
  8. Horton spheres
  9. Elliptical tanks
  10. Cryogenic & pressurised tanks
  11. Wooden vats and casks
  • Application of the most appropriate method and a through understanding of the characteristic andgeometry of a particular tank is absolutely essential. Here is where long years of experience, engineeringand mathemetical background in indispensible.
  • Guidelines are laid down by the weights & measures department and also international standards like as ISO 7507 and API standard 2552 can be followed to calibrate your tanks.
  • Internal inspection is carried out in tanks where it is safe to enter enabling us to measure datum plates andinternal deadwood. underground Horizontal tanks require internal measurements. Bottom plate unevennessis profiled and physical calibration with water is done upto flush point.
  • All field data are fed into oue computer with specific software for specific linear corrections like tape temperature corrections, thickness corrections, deadwood corrections, etc. and shell wise calculations as per international ISO methods and rules laid down by the Weights & Measures Dept. Complex mathematical formulae and calculations are involved in case of Horizontal tanks and spheres where volume increments increase and decrease in a non-linear manner. No averaging process is carried out as is done elsewhere.
  • Calibration charts are made in centimeter and liter, to the fraction of the nearest millimeter. For spirit tanks under excise gauging tables are computed at 2mm intervals as per rule. Calibration charts can also be given in kilograms where liquid (With known specific gravity) is measured by weight in some cases.
  • Tank calibaration data can also be provided on CD/email for SAP and other integration.

Measurements Process at Site on Tank:

  • External Tank Strapping method (ISO 7505 Part 1) and Part ii of 9th, Schedule of the Standards of Weights & Measures (General) Rules 2011.
  • Datum plate height with reference to individual course heights.
  • Determination of Dip-reference height and point of gauging.
  • Inclination & Spherical dish-end measure of horizontal tanks.
  • Calibration of pressurized Spherical tanks and horizontal bullets: internal vertical and
  • horizontal diameters, position of magnetic servo float with respect to bottom.
  • Internal deadwood measurements.
  • Ultrasonic Plate thickness measure.

Physical Calibration Process at Site in Tank:

  • Determination of flush point of bottom of vertical cylindrical tanks by water through flow meter.
  • Physical calibration of uneven conical or spherical bottom of tanks and spirit vats up to the datum plate of vertical cyl. portion.
  • Floatation of roof of floating roof tanks by water to determine volume displacement by weight of the roof. This displacement is to be applied for density corrections of liquid stored.
  • Complete physical calibration is required for deformed underground FRP horizontal tanks which have lost its cylindrical shape, in measured intervals through accurately calibrated flow meter and data recorded for later processing and interpolation of volume into even segments.

Why Calibration is essential:

    We are ready to give our Door Step service for our Customers Satisfaction



    On the above subject U/s has to stay that as per the provision of section 27 of the Standard -Weight & Measure general Act 2011 no Weights & Measures shall

    be sold or offered Possessed for sale use of kept for use in any transaction or for Industrial Production or Protection unless it has been verified & stamped and as provided in rule 2011 framed under the said Act the storage tanks including Vatsused or intended to be used in any transaction, or for Industrial Protection re-verified or re-calibrated and stamp at least once in five year. The definition of the word "Transaction" provided in section 2(U) of the Standard legal metrology act 2009 which runs have been Follows.

    1. any contract for Sale, Purchase, Exchange or any other purpose.
    2. any assessment of Royalty, Toll or other dues.
    3. any assessment of work done, wages dues or service rendered, their Storage tank can't be excluded from the purview of the above said Act & Rules. For ISO quality certification of Calibration of Storage Tank is essential accurately required by ISO official.
  • To meet central Excise / State Excise & custom Duty obligation in view of the aforesaid it is essential to get storage tank calibrated by owners and to get rid of any legal action as provided in the said Act.
  • Fines & seizures for noncompliance.
  • All Under One Roof


Scope of Work:

Our scope of work includes all associated work required for calibration of the tanks including supply of skilled and unskilled labour coordination with the official of legal metrology department, preparation of computerised calibration chart and obtaining approval, from Legal Metrology department, Strapping (Linear & Nonlinear measurement) bottom calibration through flow meter arrangement, arrangement of measuring instrument, submission of calibration chart with your floppy for your record ultrasonic plate thickness measurement with digital meter for all the shell including report as required, volumetric analysis and computation layout & drawing for calibration work. We will stay near your site for smooth running of calibration work, we will arrange for required insurance for any claim arising out of any accident to our staff and personal at the time of executing the work. You have to arrange water for calibration work.(Physical calibration) We will maintain safety measure and all rules and regulation required for explosive bonded tanks.

We will submit approved calibration chart with floppy and drawing within very short time and we will submit proforma chart within 48 hours to your part. We assure best service always, if we get said order we will start the work immediately if required, we are looking for a valued work order from your esteemed Company.

Our mission/goal for modernisation (subject to weights & measure approval)

  • If required, safe Laser beam measurements are also used for internal diameter measurements, specifically for horton spheres and underground cylindrical tanks.
  • A combinational of traditional physical calibration to the latest laser distance ranging and optical triangulation technology may be required to acquire all the necessary field data of any tank. Every tank may require different methods and approaches to achieve accurate data.
  • Inaccessible and risky positions on vertical tanks where personnel are traditionally require on a high scaffolding to strap the tank circumference with strapping tapes at a certain tension has been done with. Laser and optical technologies give our clients the beefit accuracy, safety and reduced costs.
  • External & Internal laser distance tranging
  • External radius at all levels of large vertical tanks by optical triangulation method (ISO-7507 - Part - 3 )
  • Optical measurements of diameter after allowing shell expansion for tanks operating at high temperature for product storage, specially in large dia F.O. tanks