The Best of the Best--a biennial update on our basic inspection tools. (Tools for Environmental Health).

It's that time again, when we present our biennial Best of the Best in field instrumentation. Over the past two years, we have had the opportunity to work with some of the latest innovations in field instrumentation, as well as those old and familiar pieces of equipment that have been serving us well since we started this column in 1997. Please be assured that the instruments presented in this column are the ones we regularly use on the job, and that we buy most of our instruments. Those that are donated are done so with no strings attached. If they don't pass muster, so be it. Our motto remains: No special dispensation for largesse.

But first, a bit of background on how we evaluate the equipment we write about. We are both professional sanitarians with active forensic and institutional practices. We regularly conduct audits, inspections, and evaluations in a variety of settings, most of which are in correctional environments. Prisons and jails have everything necessary to sustain a reasonable quality of life that one would expect in a world without restricted movement: food, laundry, personal hygiene, water and wastewater, air quality, lighting, noise, occupational health, housekeeping, solid waste, medical care, recreation--you get the picture. Once we are inside the institution, there is little opportunity to run back to the car to retrieve a specialized piece of equipment to help us measure a problematic environmental parameter. Therefore, we have certain expectations of the instruments that we take in with us. Our field instruments should be

* portable--preferably small and lightweight, as well as nonreactive, rugged, and safe to use;

* disposable, easily decontaminated, or easily protected from contamination;

* relatively inexpensive and, if powered, should run on "standard" batteries;

* simple and easy to operate with one hand;

* accurate and easy to read, calibrate, or validate;

* not subject to interference or damage by adverse environmental conditions or transportation;

* able to provide direct readings of results requiring minimal interpretation of results, and

* adherent to standard protocols whenever possible or practical. But, most important, we expect our field instruments to be versatile, so that we are able to take accurate and numerous measurements in a myriad of different settings.

When we conduct the initial evaluation of any instrument, we use a check sheet on which we list these attributes (although the list is much expanded) and grade each attribute from A to F, according to the unit's performance in the field. Generally, only instruments that receive a grade of C or better with respect to all our expectations will make this column, with a few exceptions due to uniqueness or particular usefulness. Needless to say, over the past several years, we have become a trifle more discriminating and, for better or worse, more objective in our selection of tools that accompany us to our job sites.

Because we use our instruments in support of forensic inspections and evaluations, we have had to defend our choices and uses of these instruments on more than one occasion. We are pleased to say that our recommendations have held up under rather intense questioning in both testimony and deposition.

Thermometry 

Thermometry is the backbone of our practice. The more we use the variety of thermometers available to us, the more proficient we become, and consequently our preferences change. Therefore, we have felt it necessary to provide a little more detail about our selections. So, without further ado--to use a hackneyed expression--here is our basic tool kit.

Bimetal Thermometer

The bimetal dial thermometer is our handiest and probably our most versatile tool. We use it for almost all noncritical temperature measurements, particularly in those areas where we can place the thermometer, go about our business, and retrieve it later when it has finally equilibrated. We insist that this mainstay of our profession meet two criteria: The first is that the numerals on the dials be large and crisp, and that the dial lens make the numerals easy to read, even under lower-light conditions. We prefer a lens with a bit of magnification. Second, we only use thermometers that have been manufactured to a public-health standard, which means we buy only those bearing the NSF mark. This policy is our insurance that the thermometer will not impart anything to the food, even when used in low-pH situations, and that with regular calibration, it will be consistently accurate within specifications. Our top choice and the one that best meets our criteria is the bimetal dial thermometer manufactured by Cooper Instrument Corporation (<http://www.cooperinstrument.com>).

Thermocouple Thermometer

The needle-probe thermocouple thermometer is still our mainstay when we conduct food service inspections--and for good reason: It is convenient, fast, and accurate. While all thermocouple thermometers demonstrate about the same performance, there are distinct differences among brands. Over the past few years, we have evaluated about a dozen of the more commonly encountered units used by our profession. The ones we favor have a few characteristics in common: First, the K-type connector is integral to the unit and does not serve as a catch area for food; nor are there any sharp edges where the male plug is connected to the cord (the notable exception is in our HACCP kit, where we use several interchangeable probes). Second, we like the instruments powered by the less expensive AA-size battery, which is held in the unit with a threaded waterproof closure. Third, we like to see the NSF mark on the unit, for the reason stated above. And finally, since the thermocouple thermometer is the one most frequently used du ring inspections, we want the instrument to be easy to read, rugged, and cleanable. For these reasons, we are still quite partial to the Atkins Series 340 (<http://www.atkinstech.com>). The Cooper FW 2000 is a close second choice.

Thermistor Thermometer

When we need a waterproof electronic min/max-registering thermometer, we use the DeltaTRAK maximum-registering thermometer we affectionately call "the Lollipop." The buttons on the Lollipop are easy to operate by feel, which comes in handy for measuring shower temperatures--only an arm gets wet. By and large, this thermistor thermometer does not exactly conform to our preferences. We have made allowances because of its convenience, however. For instance, in spite of our pleadings, DeltaTRAK (<http://www.deltatrak.com>) has not changed the pocket clip to accommodate the top-heavy unit. Therefore, when we get a new "Lollipop", we immediately break off the molded plastic clip, leaving the loop in place, and install a 5-cent pencil clip "upside-down" so that the heavy end of the Lollipop is pointed downward. The maximum-registering capability is also ideal for measuring dishwasher final-rinse temperatures, but the LED display has to be protected from the heat. We use a plastic Caboodle[R] cosmetic case to cover t he electronics yet allow exposure of the probe; these cases are available in most discount stores.

Infrared Thermometers

We first introduced the infrared thermometer in the May 1997 issue of the Journal. Since then, we have had considerable practice in its use; we were active participants on the UL 2333 Standard Committee, and we believe that we were the first to use the infrared thermometer as a recognized quality control tool for public health in a court of law. For five years, our preferences were rather catholic; it seemed as if every month a newer and more improved unit would be introduced to our profession. Recently, however, we formalized our preferences to two selections; both have laser aiming. One is used with food, and the other for everything else, the two models complement each other.

Our food infrared thermometer is the Raytek[R] MiniTemp FS[TM] (<http://www.raytek.com>). Its emissivity is preset at 0.97, aiming is a single-dot laser, and it has an aspect ratio of 1:4, which makes it ideal for food work. In addition, the Raytek thermometer is of ergonomic design; the display is backlit for low-light conditions, the holster fits nicely on the belt, and it is very easy to change the battery. In short, the MiniTemp FS is the most comfortable unit in the field.

Our choice for everything else is the Omega[R] OS643-LS (<http://www.omega.com>), for two reasons. The Omega OS643-LS has a long aspect ratio with circular laser sighting. This feature lets us take temperature measurements at a considerable distance from the source and the circular laser pattern outlines the area we are measuring. We use this instrument to measure incoming air from ceiling registers, effects of radiant heat, ambient temperatures from internal surfaces, and hotspots on mechanical and electrical systems.

Single-Use Paper Thermometer

Although paper thermometers are not our first choice, we have found them to be convenient and quite accurate. For the past two years, we have come to rely exclusively on the self-adhering Thermolabel Dishwasher Labels, manufactured by the Paper Thermometer Company (<http://www.mv.com/ipusers/paperthermometer>). Our reasons for this selection are the following: First, the self-adhering label works on any porcelain or metal surface. Second, the Thermolabel measures the temperature on a heat sink. Third, the label is accurate to within 1 percent of the calibrated temperature, and it also serves as a permanent record on the inspection report.

Flashlight

For years, we have used a basic AA-cell halogen flashlight featuring one-handed operation. Now, however, we have ratcheted our flashlight up a notch with new technology. Our latest constant companion is the Streamlight 4AA ProPolymer LED flashlight (<http://www.streamlight-flashlights.com>). This flashlight uses four AA batteries and features seven LED bulbs that produce an extremely intense white light. While the Streamlight cannot be adjusted to produce a spot, its light provides startling visual contrast, thereby making it easier to pick out insect and rodent damage, water leaks and chronic wetness, and general soiling. The flashlight is ruggedly built and features a protected on/off switch. The battery life exceeds that of the halogen lights.

Light Meter

We still are partial to the Type 217 GE light meter, which is available through most scientific catalogues. It is the ideal portable instrument: small, rugged, versatile, and lightweight--and it uses the light it measures as its energy source; therefore, no batteries. Its only drawback is that it cannot measure illumination below 10 foot-candles, a capacity needed when you are evaluating a facility for compliance with the National Fire Protection Association Life Safety Code[R].

Electrical Safety

We still rely on two small instruments to ensure our own safety and to detect most electrical problems. The A/C Sensor, which is slightly larger than a pen, simply indicates the presence of electrical current when held close to a live source or piece of equipment. We also carry with us a ground fault circuit interrupter (GFCI)/receptacle tester to check the wiring configuration of outlets and the GFCI. Both are available in most hardware stores.

Ventilation

To characterize ventilation, we rely on the Flowchecker[TM], a small squeeze bottle that contains amorphous silicon dioxide powder, or on a small, empty nasal spray bottle that contains zinc stearate powder. To complement this low-tech "if-and-where" tool, we also take along the inexpensive and compact Dwyer 460 Air Meter (<http://www.dwyer-inst.com>), just in case we need a velocity or static-pressure measurement.

Temperature and Humidity Measurement

For rapidly and accurately measuring both temperature and humidity in any area, we have come to rely on generic compact digital thermohygrometers, which are about the same size as an AA-cell flashlight. These instruments are available through most scientific catalogs.

ADA Compliance

We have always contended that any establishment that meets Americans with Disabilities Act (ADA) requirements is also safe for the general public. Therefore, we always include an 8-foot tape measure in our inspection kit. It has universal application--both for ADA and for measuring other critical areas in institutions. In addition, we include a pen-sized door pressure gauge and a 1:20/1:12 ramp-slope bubble measuring device in our kit. The pressure gauge and ramp-slope bubble measuring device are manufactured by HMC of Littleton, Colorado (<http://www.hmc-international.com>).

Indicator Papers

We still prefer the versatile Watman[R] Type CF 0-14 pH indicator papers. We also use Code 4250-BJ, acid-free LaMotte Chlorine Test Papers, whose end-point color is the easiest to interpret. The small LaMotte soil pH kit is ideal for measuring the pH of sushi rice.

Necessary Peripherals

Our basic inspection kits also contain the following: a hardcover, bound notebook and a date-recording 35-millimeter (35-mm) camera; wooden-stick cotton swabs to show where the dirt really is; a small awl or ice pick for making a hole in frozen food; self-sealing quart-sized plastic bags; a collapsible inspection mirror (Sears Craftsman); vinyl disposable exam gloves; and a brimmed white or taupe cap with the word "Sanitarian" embroidered on it. We still have not found any carrying case better than a GI-issue, Korean War-era, 50-mm ammunition carrier--or a washable tool bag with a single-zipper top opening and internal and external side pockets.

Cost

Our basic kit, consisting of everything listed above, including the additional infrared thermometer, costs about $700.

Postscript

In addition to the basic tools, we also regularly carry the compact [Pa.sub.w]kit, manufactured by Decagon Devices, Inc. (<http://www.decagon.com>). The [Pa.sub.w]kit is a field kit for measuring water activity in foods, and we find it most useful in separating foods requiring refrigeration from those that do not. Because of its higher price tag, we have not included it in the basic kit, but we urge anyone who routinely inspects confectioners, ice cream parlors, or larger institutional kitchens to include its purchase in your next budget cycle.

As we stated in our previous Best of the Best articles: If we have left anything out, or if you have any ideas for other field instrumentation or peripheral supplies, please send your thoughts to us in care of the Journal at NEHA, 720 S. Colorado Blvd., #970-S, Denver, CO 80246. We welcome your input and promise that we will present all recommendations, ideas, and suggestions in future articles.

This article is provided by NEHA for informational purposes only. It is designed to better inform our members about topical and relevant goods and services available to the environmental health professional. Opinions expressed about any product or service in this column either expressly or implied are solely and completely those of the author/s and do not necessarily represent the views or opinions of the National Environmental Health Association.