While it is neither practical nor possible to service some very old
models, Narda continues to calibrate almost all the radiation safety
products that it has built since 1990. The most common services provided
are calibration, repair, and the supply of spare parts.
The section below describes our capabilities and procedures. The section How To Obtain Service is important. Please follow the guidelines in that section – they allow Narda to provide you with the quickest possible service.
Narda Safety test Solutions, Hauppauge, New York Narda can calibrate any model RF safety product it has ever built. We can usually repair almost any damaged unit providing that parts are available. Parts availability is rarely an issue for any item that is less than 15 years old (see Repair Categories).
Narda can calibrate probes under CW conditions at the following frequencies:
3 kHz to 1100 MHz (any frequency)
1800 MHz to 45.5 GHz (any frequency)
Narda Safety Test Solutions
435 Moreland Road
Hauppauge, NY 11788
Attention: Customer Service
Narda Safety Test Solutions, Pfullingen, Germany
Narda Safety Test Solutions
Link Microtek, England
Link Microtek has the ability to calibrate most RF survey equipment and NY (Nardalert and Nardalert XT) manufactured RF monitors. Calibration and Service of any Narda-STS product can be coordinated for UK customers.
Link Microtek Service Center
High Point, Church Street
Basingstoke, Hampshire RG21 7QN
Tel. 44 1256 355771
Fax. 44 1256 355118
How To Obtain Service
The most important thing you can do to receive the best calibration and repair service in the quickest time, is to use the following procedure:
1. Contact the appropriate service facility
Customers located in North America should contact Narda in New York. Customers located in the rest of the world should contact Narda-STS in Germany. For older products from each company (8600 and 8700 series from New York, and EMR series from Germany) you may be advised to contact the manufacturing entity.
2. Obtain RMA (Return Material authorization) Number
You will be asked to provide a list of the equipment. Model numbers, serial numbers, and a description of the services required will be needed. For example, if you anticipate requiring only calibration, state that. If there are indications that the equipment requires repairs, please describe the symptoms.
3. Pack the equipment well.
Meters and probes should be shipped in the original instrument case whenever possible. The instrument should then be packed inside a cardboard box. Probes, in particular, should be packed very carefully if they are not being shipped in an instrument case.
4. Authorize the calibration and/or repair charges in advance.
Narda has established fixed prices for 99% of calibration and repair work. This allows us to process your order immediately. Ideally, authorizations are not to exceed (NTE) value equal to a minor repair charge. See CALIBRATION PROCEDURES and REPAIR CATEGORIES.
5. Specify the type of calibration service required.
Most customers request our standard service. ANSI Z540 service (see below) is available at an additional charge. Priority Calibration service provides five business-day calibration (not repairs) at an additional charge.
Equipment that is received via an RMA number and with the charges authorized will be worked on immediately. Simply returning equipment without contacting us (i.e., without both an RMA number and authorization to perform the work) will result in delays.
Most Narda NY survey instruments are designed so that the meter and probes are calibrated independently of each other. The 8100, 8200, 8600, 8700 and NBM series equipment can have probes and meters interchanged within the same series with- out in any way affecting calibration. The 8500 and NIM series are supplied as a single probe and meter that are calibrated as a set. Personal monitors and area monitors are calibrated as sets.
Meters (except the 8500 series) are calibrated by using a precise DC voltage that relates to the full scale measurement range of the probes in that series.
Probes are calibrated by placing them in precise RF fields using either TEM cells or free field environments. The RF field strength is normally established to be equal to 5.0% of the full scale rating of the probe. For example, to calibrate a model 8721 electric field probe, which is rated at 20 mW/cm2, an electric field equal to 1.0 mW/cm2 is established at each calibration frequency. If the probe were perfectly flat, it would then produce an output that reads 1.0 mW/cm2 at every frequency. In practice, the probes are not perfect and some error is expected. If the probe indicates 1.1 mW/cm2, a calibration factor of 0.91 would be marked on the handle. Multiplying the calibration factor times the indicated rating provides the true value (0.91 x 1.1 +0.999). The actual procedure is to calibrate at every frequency and then to set the gain of the amplifier to center the frequency response for “best fit”.
Probes that are obviously damaged will not zero properly. Occasionally, a probe will appear to function properly but cannot be calibrated successfully. This can occur when some form of internal damage or malfunction in the RF sensor results in certain frequencies not being measured accurately. This problem necessitates some type of repair of the sensor. It is for this reason that, occasionally, a probe that appears to require calibration only, will require minor repairs (see REPAIR CATEGORIES).
Personal monitors and area monitors are calibrated in a similar manner to probes. Since there is no readout, except NS3 monitors, they are normally calibrated at a limited number of frequencies.
ANSI Z540 Calibration
Narda NY's standard calibration procedures are similar to the procedures used for new equipment. The product is adjusted as required so that it is well within specification. ANSI Z540-1- 1994 (similar to the now obsolete MIL-STD-45662A) requires that the equipment to be calibrated must first be measured to determine how it is reading before adjustment. These values are then compared to the values that the particular meter or probe was originally set to. Customers are advised in writing if a unit has changed by more than ±1.5 dB since it was last calibrated. The equipment is then calibrated in the normal manner. Equipment calibrated under these procedures receive special calibration labels and certificates. This is obviously a more involved procedure than a standard calibration and the costs are higher.
Narda NY uses several terms to define repair categories.
Standard or NIST Calibration: This is Narda’s standard calibration service that is traceable to the U.S. National Institute of Standards and Technology. Microwave oven instruments are calibrated based on comparisons with FDA.
ANSI or MIL Calibration: See ANSI Z540 CALIBRATION above.
Minor Repair: This category of repairs covers the majority of typical repairs for most models of equipment. Meters alone have separate pricing for common repair items such as replacing meter movements and rechargeable batteries. Virtually all other items to be repaired are classified as minor or major repairs. There is a fixed price for the minor and major repair of each model. Minor Repairs typically cost 25-40% more than a standard calibration.
Major Repair: Although a probe may look like it is beyond repair, it may still be salvageable and would fall under the Major Repair category. Otherwise, it will be classified Beyond Economic Repair (BER). Major Repairs typically cost 40-50% of the price of a new unit.
Beyond Economical Repair (BER): Narda classifies a piece of equipment as BER if either (1) the cost of repair and calibration will be more than 50% of the cost of a new unit or (2) it is a very old unit and parts may be unavailable or impractical to obtain.
Return As Is (RAI): Narda occasionally will return a piece of equipment without calibrating or repairing it at the discretion of the customer or if it is classified as BER. An evaluation fee is charged for equipment Returned As Is. Evaluation Fee: Narda charges a modest fee for each item that is evaluated and returned without performing a repair or calibration.