Calibration and Repair of Test Instruments

Calibration of Digital Pressure Gauges

NEW two-year calibration announced in November 2013. Learn more.

Equipment Return Form

TEC recommends the DG-700 and DG-500 digital pressure gauges be recalibrated once every two years to maintain the instrument's accuracy specifications of 1% of reading (or 0.15 Pa, whichever is greater). Calibration is performed at our facility in Minneapolis, MN (see address below). The cost to calibrate a digital pressure gauge is $80. This price includes return ground shipping within the continental 48 states and Canada (expedited or air shipments will cost more). Turn around time at our facility for calibration is typically 2-3 days following receipt of the instrument (assuming no repairs are necessary). We will provide a NIST traceable calibration certificate which includes “as found” as well as “current condition” pressure data. (DG-3 and DG-2 pressure gauges should be recalibrated once per year.)

Digital Gauge Calibration

When returning a gauge for calibration, please use the Equipment Return Form, fill it out completely, and include a copy of the completed form along with the equipment being returned. (NOTE: The Equipment Return Form now contains entry fields and can be filled out digitally on your computer. If you fill it out digitally simply print the completed form. This form can still be printed and completed by hand as well. If you are trying to fill out the PDF online using FireFox, click here.)

In lieu of sending your DG-700 or DG-500 gauge into TEC once every two years for calibration, customers may choose to perform a field calibration check procedure which is contained in the Digital Gauge Field Calibration Check documentThis document describes a procedure to field check the calibration of digital gauges against a recently calibrated DG-700 gauge that is being used as an in-house reference standard. We recommend that a field calibration check be performed annually, or whenever a gauge has been dropped or damage is suspected. Results of field calibration checks should be recorded and documented by the customer using the sample log sheets provided at the end of the calibration check document. Gagues that fail the Digital Gauge Field Calibration Check will need to be sent to TEC for recalibration.

It is also a good idea to periodically check the two channels of the DG-700 and DG-500 pressure gauge against each other to be sure they are reading very close to same value (e.g. they should always be within 1% of each other). This test will quickly isolate gauges with large problems (e.g. damaged flow sensors), and is described in the Comparing Channels on the Same Gauge document. This procedure does not replace the need for gauge recalibration once every two years.

Calibration of Blower Door and Duct Blaster Fans

TEC Blower Door and Duct Blaster fans maintain their calibration unless physical damage occurs to the fan or flow sensing system. Conditions which can degrade calibration of the fan are easily detected and should be field tested by the customer on a regular basis using the procedures contained in the Fan Field Check document  (see Fan Field Check document). This document describes a procedure to check for damaged flow sensors, leaks in the flow sensor or tubing running from the flow sensor to the fan pressure tap, or improper positioning of the flow sensor relative to the fan housing. We recommend that a field check of the fan be performed at least annually, or whenever a fan has been dropped or damage is suspected. Results of field checks should be recorded and documented and sample log sheets are provided at the end of the field check document for this purpose.

Blower Door and Duct Blaster fans can be custom calibrated at the TEC facility for $250. Custom fan calibration parameters can be easily entered into our TECTITE and TECBLAST software. Note: Custom fan calibration is not necessary for most testing applications.

Field Calibration Plate for Duct Blaster System with DG-700 Gauge

The Field Calibration Plate allows you to quickly check the calibration of the entire Duct Blaster System with DG-700 gauge. The calibration plate, which contains a 5 inch diameter hole, is simply mounted on the square transition piece that is connected to the end of the flex duct. The Duct Blaster fan is turned on to pull air through the calibration plate and simulate a duct leakage test. Results from the simulated test are compared to the known leakage rate to determine if the entire system is within a +/- 3% accuracy range. This calibration check covers the entire system, including the Duct Blaster fan, the DG-700 gauge and the flex duct.

A Duct Blaster Field Calibration Plate can be purchased for $45. Instructions for using the Calibration Plate are contained in the Duct Blaster Field Calibration Plate document.

Calibration of APT Data Acquisition Boxes

TEC recommends that APT Data Acquisition Boxes be recalibrated once per year at our facility in Minneapolis, MN (see address below). The cost to calibrate an APT Data Acquisition Box is $125. This price includes return ground shipping within the continental 48 states and Canada (expedited or air shipments will cost more). Turn around time at our facility for calibration is typically 3-4 days following receipt of the instrument (assuming no repairs are necessary).

When returning an APT Data Acquisition Box for calibration, please use the Equipment Return Form, fill it out completely, and include a copy of the completed form along with the equipment being returned.

Calibration of Magnehelic Gauges

Calibration support for Magnehelic gauges was discontinued as of January 1, 2006. Magnehelic gauges which are under a TEC warranty (2 years from date of purchase) will be serviced as usual. Although calibration support is not available after the warranty period, Magnehelic gauges can be sent to TEC to be checked for accuracy for a fee of $15 per gauge. The accuracy of the gauges will be tested and recorded, however calibration adjustments will not be performed. All gauges will be returned with a copy of the "as-found" test results. For enhanced testing accuracy, TEC recommends that Magnehelic gauges be replaced with digital pressure gauges.

Equipment Repairs

If you ever have an equipment problem, we always stock a complete line of replacement parts, and can respond quickly to any service problem. All equipment needing repairs (or calibration) should be sent to our facility at:

The Energy Conservatory
2801 21st Ave. South
Suite 160
Minneapolis, MN 55407
Attn: Equipment Repair/Calibration

When sending equipment for calibration or repairs, please use the Equipment Return Form, fill it out completely, and include a copy of the completed form along with the equipment being returned.