Calibration and Repair for Nuclear Gauges

Man using Nuclear Gauge

Calibration and Repairs



Fast and EaZy, Full-Service Nuclear Gauge Calibration, Leak Tests and Repairs

To support our customers and their use of our nuclear gauges, Humboldt maintains a complete ISO/IEC 17025: 2017 accredited repair and calibration facility at Humboldt Scientific in Raleigh, North Carolina. Here we provide repair and calibration services for Humboldt gauges, as well as those of the other manufacturers. All services are performed by experienced and certified technicians with over 25 years of experience.

Our services are built upon providing fast and reliable turn-around of your gauge calibration and repairs while maintaining competitive prices. Humboldt nuclear gauge calibration complies or exceeds ASTM and AASHTO standards by providing five-block calibration for all gauge calibrations. We maintain multiple sets of calibration blocks, which are traceable to master NIST standards. These blocks are set up in isolated, temperature-controlled bays to reduce interference during calibration.

Documentation and certificates for calibrations conform to NIST procedures and requirements. We also provide leak test analysis services, gauge rental and disposal services.

Humboldt Scientific Service Center -
ISO 17025 Accredited Calibrations

  • Load Cells - 500 lb to 10,000 lbf
  • Displacement Transducers - 0.4" to 2.00"
  • Pressure Gauges - Up to 300 psi
  • Electrical Density Gauge
  • Nuclear Density Gauge
  • Density & Moisture Blocks

Standard Calibrations (Non-ISO 17025 Accredited Calibrations)

  • Load Cells - Up to 10,000 lbf
  • Displacement Transducers - Up to 4.00"
  • Pressure Gauges - Up to 300 psi
man calibrating machine

Most organizations require that their nuclear gauges be calibrated at least once a year. Calibration ensures that nuclear gauge readings meet established standards of accuracy and repeatability established by ASTM and AASHTO standards. The calibration process is used to compare each gauge with NIST-traceable calibration blocks while documenting the complete results of the calibration process and the calibration blocks used. Humboldt nuclear gauge calibration complies or exceeds ASTM and AASHTO standards by providing a five-block calibration routine for all gauge calibrations.

We offer five-block calibrations, even though it requires more time, because we believe the added blocks provide a much more accurate calibration for nuclear gauges. We maintain multiple sets of calibration blocks, which are set up in isolated, temperature and humidity controlled bays to reduce interference with other gauges during calibration and provide a consistent and regulated atmosphere during calibration operations. All sets of calibration blocks have been manufactured to be identical in construction and composition. The densities of these calibration blocks are traceable to NIST master standards, which are maintained through periodic, documented calibration to the master standard.

Humboldt maintains all documented history of calibration of our blocks and their calibration procedures. This includes procedures, internal assurance policies, test data, calibration records, NIST standards documentation and uncertainty computations for all blocks and calibration devices. This documented data provides clear evidence of Humboldt’s ability to provide you with reliable and accurate nuclear gauge calibrations. All Humboldt calibrations include a complete gauge inspection, which include:

  • NIST Traceable Calibration
  • Replacement of routine maintenance items: gaskets, seals, labels, scraper ring, etc.
  • Complete electronic system analysis and adjustment
  • Mechanical and source rod inspection
  • Cleaning and lubrication
  • Leak test
Fill Out The Form

Need to ship your gauge to us for calibration or repairs?
Let us handle it!

To make using our services as easy as possible, we have designed our EaZy shipping program. Just go to our website and fill out the calibration/repair form and we’ll handle the rest. We will send you the completed shipping papers your gauge will need to have for shipping to us and directions on how to prepare and pack your gauge for shipment. We will then contact the carrier and have them pick up your gauge from your designated location and ship it back to your licensed address when the calibration is completed.

Fill Out The Form

Survey Meter Calibration



Survey Meter Calibration

Survey Meter Calibration Includes:

  • NIST traceable Calibration Certificate with all applicable data.
  • Calibrated using a Cs137 (662keV) beam calibrator.
  • Conforms to ANSI/NSC SLZ540.1.1994 and ANSI N323-1978.
  • ANSI Z540.3.2006 upon request
  • Traceable to NIST DG8640/87
  • New Batteries

When shipping your meter to us for calibration, please fill out our RMA Form (Return Materials Authorization), print it and pack it with your meter for shipping.


Contact Us


Leak Test Certificate

If your gauge is Damaged: If the gauge you wish to ship is damaged and you want to send it to us for repair or disposal, you must call us at 1.800.537.4183 for prior approval. We will require that you send us photos, as well as a leak test, which has been performed on the gauge after the damage was inflicted.

Leak Test Service


leak test

Humboldt provides leak test kits and analysis services for all portable and fixed nuclear gauges. Click here to purchase Leak Test Kits. Humboldt is licensed by the North Carolina Division of Radiation Protection to provide sealed-source leak testing; and, has National reciprocity recognition. State-of-the-art leak testing equipment, low cost, and prompt turn-around service ensures accurate and convenient measurement of your Cs-137 and Am-BE:241 samples.

Leak Test Shipping

First, you will need a current, valid leak test for the gauge you wish to ship, before shipping it. Be sure to correctly indicate a valid leak test is available when you fill out the Humboldt RMA form in the next step. If you don’t have a valid leak test, you can purchase leak test kits from Humboldt, perform the test, and send it to Humboldt for evaluation. You will then be sent a valid leak test certificate, which you can then refer to on your RMA form.

Purchase Leak Test Kit

Gauge Disposal



Parts and Disposal

Humboldt Gauge Disposal / Return of Radioactive Material Policy

Humboldt Scientific, Inc. is authorized to receive nuclear gauges for disposal manufactured by Humboldt or competitors under radioactive material license number 092-0750-1 issued by the State of North Carolina.

This includes both your need to terminate use of device or source exchange if a replacement is required.

Nuclear Gauge Return Form