Research Paper
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Hazard Control Peer-Reviewed
Keeping Workers on the Ground By Albert Weaver III and Cynthia H. Sink
F all injuries, both on the same level and to a lower level, remain among the most dis- abling injuries in the U.S. Researchers at
Liberty Mutual Research Institute for Safety (2014) examined Bureau of Labor Statistics (BLS) injury data of all workplace injuries to determine which events caused an employee to miss 6 or more days of work, then ranked those events by total workers’ compensation costs. The results of their examina-
tion showed that the leading causes and direct costs of the most disabling work- place injuries in 2012 were:
1) overexertion involving an outside source;
2) falls on the same level; 3) struck by an object or equipment; 4) falls to a lower level. Falls to a lower level accounted for $5.12
billion in costs in 2012. According to Feder- al Highway Administration (FHWA, 2014) 2,643,567 million ton-miles of freight were transported in the U.S. during 2011 (a ton- mile is a single ton of goods that is trans- ported for 1 mile). Collecting the following data involving semis, tractor-trailers and tanker trucks due to falls to a lower level, BLS (2016) reports that between 2011 and 2013, 7,450 nonfatal occupational inju- ries and illnesses occurred involving days away from work and 44 fatalities. This is BLS category code 8421 including tanker trucks and flatbed trucks except straight trucks, logging trucks and car haulers.
It also excludes fire trucks, which are category 8425. Federal Motor Carrier Safety Administration defines semitrailer as “any motor vehicle, other than a pole trailer, which is designed to be drawn by another mo- tor vehicle and is constructed so that some part of its weight rests upon the self-propelled towing motor ve- hicle” (Federal Motor Carrier Safety Regulations).
Cargo Tank Truck Falling Hazards When loading a cargo tanker, climbing on top to
observe the fill level creates a fall hazard. Adding to the possibility of having a fall, certain cargo can create hazardous gases or slick surfaces. According to Cargo Tank Risk Management Committee (CTRMC, 2014), the top 10 reasons (not ranked) that workers climb atop transportation tanks are to:
1) ensure security; 2) check equipment; 3) extract samples; 4) load/unload product; 5) assess liquid content levels; 6) initiate air unloading or vapor recovery; 7) perform maintenance and inspections; 8) wash tanks; 9) remove snow; 10) discharge heel (any material remaining in a
tank following unloading, delivery or discharge of the transported cargo).
Case Studies The following case studies exemplify falls from
tanker trucks where the cargo transported fell out- side DOT regulations for gauges on tankers.
Albert Weaver III, CSP, is president of L.A. Weaver Co. Inc., an occupational and environmental consultancy. He holds an under- graduate degree from Western Carolina University and an M.S. in Industrial Engineering from North Carolina State University, where he was a NIOSH fellowship recipient. Weaver was an adjunct faculty member for 2 years and a lecturer for the engineering extension for 20 years. He is a 40-year professional member of ASSE’s North Caro- lina Chapter, which he has served twice as president. In addition, he is member of the Society’s Environmental Practice Specialty, for
which he was a founding member and past administrator, and a past administrator of the Consultants Practice Specialty.
Cynthia H. Sink is an engineering intern at L.A. Weaver Co. Inc. She is a senior in the Industrial and Systems Engineering program at North Carolina State University with an anticipated graduation date of 2016. Prior to this, she worked for several large manufacturing and service firms in North Carolina and Virginia.
In BrIef •Working on top of cargo tankers presents risks such as falling and exposure to hazardous materials. •Using a fill-level gauge to determine the fill level can eliminate the need for personnel to be on top of a cargo tanker. •Considerations for in- stalling a fill-level gauge include pricing, safety and applicability to the material being transported. •With the cost of fill-level gauges starting at $40, their addition to cargo tankers increases worker safety with- out placing an undue cost burden on the transporter.
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Keeping Workers on the Ground
Falls From Cargo Tankers
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The addition of a fill-level gauge to a cargo tanker
increases the safety of the
workers filling the tank without placing an undue cost burden on the transporter.
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Case Study #1 During the process of loading blood and discarded
turkey parts at a turkey processing plant, the driver climbed the truck-mounted ladder on the side of the truck to check the fill level of the blood tank as it was being loaded. The driver needed to stand on top of the truck to hold onto the blood pipe while looking down into the tank to determine when it was full or if the weight limit had been reached. The truck was not equipped with a fill gauge.
When the tank was full, he instructed a processing plant employee to cut off the blood flow into the tank. After bending over the tank as if he were sick, he fell approximately 10 ft onto a concrete floor, striking his head. He died 2 days later. The autopsy report noted that the cause of death was aspiration pneumonia with contributing causes of blunt force trauma to the head.
The decedent was working in an environment with the potential of producing hydrogen sulfide. Although it is a recognized hazard in the meat processing in- dustry, it is unknown whether the processing plant personnel involved in the loading process or the driv- er who was fatally injured knew of the hazard.
Case Study #2 A wastewater management employee at a hog
processing plant was transferring hog waste sludge containing decayed and fermented pig parts, urine, feces, fat, grease and hair from an overhead stor- age tank to a tanker truck for shipment off-site. After starting the gravity flow of the waste into the tanker, the employee remained on top of the tanker truck. In accordance with company policy, he was wear-
ing a personal fall arrest system (PFAS) anchored overhead. The transport company was aware of the possible production of hydrogen sulfide gas by the anaerobic breakdown of waste.
Due to the cool outside temperature and the warmth of the sludge being loaded, a thick fog was generated, hindering visibility. Within minutes of start- ing the loading process, the truck driver noticed a lack of motion by the employee on top of the tank- er. The driver found the employee motionless and slumped over, his head in the tanker’s hatch open- ing and the sludge still running. Another worker noted that employees were unhooking the harness so that they could bend over the hatch opening to check the tank fill level. The wastewater employee suffered a fa- tal injury from inhalation of hydrogen sulfide gas. The truck was not equipped with a fill gauge.
Case Study #3 A fuel oil tank truck delivery employee was loading
fuel at a transfer station. The truck held approximately 3,200 gallons, the typical size for home delivery vehi- cles. The employee had parked his tank truck beside the fuel loading rack at the oil company and climbed the steps of a 48-in.-high platform. After removing the tank hatch and setting the downspout into the tank to load fuel oil, the driver climbed to the top of the fuel truck and onto the fuel spill reservoir/platform to observe the filling process.
After an unusually long period, plant workers no- ticed the truck still at the platform. After searching the truck, workers found the delivery employee in the driver’s side cab of his truck, leaning against the
Gauge Types Quick Reference
Type Physical basis/principle Advantages Constraints/limitations Cost range Sight eye (type of sight glass)
Visual indication Simplicity; can retrofit Volume known only to level visible; may need cleaning after each use; subject to breakage; should carry a spare glass.
≈ $40 for 5-‐in. diameter part plus cost to install
Threaded rod gauge
Visual indication Simplicity; can retrofit Worker must be at cargo tanker opening to see the fill level.
≈ $30 for nuts, fender washer, and threaded rod plus cost to install
Sight tube Hydrostatic head Simplicity; can retrofit; can manufacture with parts from plumbing supply store
Subject to breakage, should install with a cut-‐off valve; viscosity is an issue, may clog with thicker substances; may freeze with certain substances in cold weather.
≈ $170 for materials plus labor to assemble and install
Float gauge Visual indication Simplicity; can retrofit Certain product characteristics, such as a sticky coating forming on the float, can make this gauge inaccurate.
≈ $230 for part plus cost to install
Load cell (a.k.a. strain gauge device)
Essentially a mechanical support member or bracket equipped with one or more sensors that detect small distortions in the support member
Weighing system requirements must be a paramount consideration throughout initial vessel support and piping design, or performance is quickly degraded (Hambrice & Hopper, 2004).
Cost; not conducive to retrofitting; vessel support structure and connecting piping must be designed around requirements of floating substructure; need to know specific gravity of liquid hauling.
≈ $10,000
Ultrasonic level sensor
Measure the time required for a sound wave to travel from the emitter to the object’s surface and return to the detector
Not subject to deterioration due to corrosive, viscous, coating and scaling liquids; accuracy.
Do not work well with liquids with foam, heavy vapor, turbulence.
≈ $760 plus cost to install
Radar Uses guided wave radar to measure the liquid level or volume in mobile tanks
Precise; for bulk solids, slurries, and opaque liquids such as dirty sumps, milk and liquid styrene, even in vapor and foam; can retrofit; ideal for vessels with numerous obstructions.
Cost ≈ $1,393
Table 1
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glass, bleeding and incoherent. Hair and blood on the ground on the passenger side of the truck indicated the site of the employee’s landing after falling from the top of the truck. The employee suffered a broken left shoulder, broken ribs, broken back and head injuries.
A threaded rod with brass washers acting as a fill gauge (Figure 1 shows an exemplar) mounted to the inside of the hatch allowed the employee to view the fill level while standing on the loading platform (load- ing rack). The side of the truck, pulled alongside the loading platform, acted as a barrier, which would have protected him from falling from the platform. However, the employee claimed he was too short to see the gauge while standing on the platform, so he climbed on top of the truck for a better view.
In these case studies, the injuries occurred after the employee climbed onto the cargo tanker to de- termine the fill level. Knowing the fill level of the tank is important for safety. Although this article discusses the types of gauges that could be used to avoid the aboveground exposure, other usual and customary injury prevention controls could be employed, such as pretask assessments for evalua- tion of confined space hazards, respiratory hazard assessments, use of personal and area hydrogen sulfide monitoring, personal worker-down alarm systems, automatic fill line shut-off technologies and hermetical seals at the junction of the waste discharge and tank hatch openings.
Although not applicable to the type of tank trucks and loading racks in these three cases, other loss prevention technologies are employed at some tank loading facilities. Railings can be constructed that surround the work area on the top of the tank. Gantry systems, designed for the type of cargo tankers used, can be moveable or permanently in- stalled to prevent falls. Cargo tankers can have cat- walks or tank top walkways with railings installed to prevent falls, and overhead anchored fall arrest systems can be used to reduce the severity of falls.
Determining Fill Levels in Tank Trucks Various types of systems are used to determine
the fill level of tankers of which the gauges cov- ered here are only part. More complex methods in- clude metering skids, weight systems and bottom
loading. Composed of one or more flowmeters, a metering skid is a framed device on which various assemblies are installed to aid in custody transfer, that is gallons of product (Petropedia, 2016).
Top loading and bottom loading involve tank- ers being filled at loading gantries either by loading from the top or from the bottom, with or without vapor recovery systems. Top loading uses an ar- ticulating arm inserted into the tank compartment through a hatch on top of the truck. A long fill pipe extends to the bottom of the compartment. Liquid level rapidly covers the bottom opening of the fill pipe resulting in low vapor generation. Bot- tom loading uses a hose or flexible arm attached to the bottom of the tanker. Vapor generation is minimized by the introduction of liquid through the bottom of the tanker compartment (BP Safety Group, 2008).
Equipping tankers or the source of the cargo with an automatic shut-off valve allows the opera- tor to monitor the fill level from the ground. Auto- matic shut-off technology has been in use since the early 1940s (U.S. Patent No. US2316934 A, 1943) and has been used in many different industries. By using an automatic shut-off system, the worker no longer needs to stand on top of the tanker while the tank is filling.
Automatic shut-off valves work with an electronic gauging system. The gauge measures the fill level and when the tank is filled to a predetermined level, the filling system automatically shuts off (W. Graham, personal communication, July 7, 2014). The system requires companies to alter the filling process by us- ing a power take off (PTO) pump to fill the tankers rather than gravity. The PTO pump is powered from the running engine of the tanker truck. Another type of system is an overflow prevention system that uses a gauging system to control the automatic shut off. Once the liquid level reaches the desired shut off point, the engine will automatically turn off, thus re- moving the power to the pump. This eliminates the need for workers to be on top of the tanker to manu- ally shut off a filling mechanism.
Gauges Reviewed Keeping personnel on the ground while load-
ing can be facilitated by the use of fill-level gauges. Many types of gauges ranging in price and com- plexity are available. Cargo tankers can be retro- fitted with low-tech and less expensive gauges, or high-tech gauges that provide greater accuracy
Figure 2
Sight Eye Sight eyes
Figure 1
Threaded Rod Threaded rod gauge
Brass fill-level indicators
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and convenience. Following are several examples of these gauges. Table 1 (p. 30) lists common types of gauges and their characteristics.
Sight Eye One of the simplest and lowest cost gauges is
a sight eye gauge. This is a glass or plastic bowl design with an aluminum or metal framework to support the bowl that can be retrofitted to a cargo tanker (Figure 2, p. 31). The bowl of the sight eye provides a visual indication of the fluid level in the tank. Sight eyes are usually attached to the cargo tank at the rear of the tank where the surface of the tank is less curved. A hole is cut into the cargo tank the size of the circumference of the sight eye base, then the sight eye is welded to the cargo tank.
Typically three sight eyes are used to indicate a low, medium and maximum level in the cargo tank by installing them at the different corresponding heights. Once installed, the sight eyes can be used to view the fluid level in a tanker without having to access the top of the tanker.
The cost of a 5-in. sight eye is approximately $40 plus the cost of installation. Fill-level informa- tion received from the sight eyes is limited since the volume is known only to the extent of the level of the sight eye. The bowl can break or become dirty making the fill level no longer visible. Also, the consistency of the liquid must be such that the bowl can fill. A semiliquid substance such as a sludge with large semisolids may block the 5-in. bowl and the bowl may not fill correctly.
A sight eye should not be confused with a sight glass. A sight glass is a glass tube, or a glass-faced section of a process line, used for sighting liquid levels or taking manometer readings.
Sight Tube Another inexpensive liquid fill-level gauge for
cargo tankers is a sight tube. A sight tube, like the one shown in Figure 3, is a glass tube used for sight- ing liquid levels or taking manometer readings. As the liquid level in a vessel rises or falls the liquid in the glass tube will also rise or fall. The gauges are made of glass, plastic or combination of the two materials (Tomsic & Hodder, 2000).
Sight tubes are simple and can be retrofitted to
cargo tankers. As the liquid fills the tanker, the sight tube will maintain the same level of fluid, thus giv- ing a visual indicator of the tanker’s fill level (Figure 4). Parts to assemble a sight tube cost approximately $170; installation, cutting holes into the cargo tank, welding the pipe-fittings and assembling the parts are additional costs. Use of a sight tube is ham- pered by severe cold weather, which may cause the contents of the tube to freeze. Also viscosity of the liquid may be an issue. If the liquid is too thick or contains semisolids, it may not fill the tube. Another concern is the gauge’s ability to withstand impact; since the tube stands out or away from the tank, the tube is subject to breaking.
Threaded Rod A threaded rod gauge is also used in some cargo
tank trucks. The gauge is a threaded rod welded to the top lip of the tank hatch with brass or other nonspark- ing, nonferrous metal washers threaded onto the rod at the height(s) the cargo is to be loaded (Figure 1, p. 31).
Float Gauge Similarly low tech, a float gauge can be retrofitted to
a cargo tank. Floats are buoyed on the liquid’s surface; therefore, the density of the float must be less than the density of the liquid. The position of the float is ob- served visually by an indicator arm, which is external to the tank. A float gauge consists of a ball float at the end of a rod (Figure 5). The rod is placed through the side of a cargo tank and an arrow is attached to the rod’s exterior end. As the liquid level rises, so does the float and the arrow attached to the exterior end of the float, indicating the tanker’s fill level. Float gauges cost approximately $230 plus installation. Liquids that may form a sticky coating on the float, such as a resin, could interfere with the accuracy of the gauge (Emerson Pro- cess Management, 2006).
Load Cells Alternatively, load cells are complex and ex-
pensive, but provide greater accuracy when deter- mining the fill volume (Figure 6). As explained by Webster and Eren (2014), “The strain-gauge load cell consists of a structure that elastically deforms when subjected to a force and a strain-gauge net- work that produces an electric signal proportional to this deformation” (pp. 41-44). Load cells, also known as strain gauges, are essentially sensors that
Figure 3
Sight Tube Tube clamped with radiator clamps to front of trailer
Clear tubing
Figure 4
Sight Tube Clear sight tube
DANGER Relieve all tank pressure before opening cover
DANGER Confined Space
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measure the strain or distortions of the framework supporting the tank (Hambrice & Hopper, 2004). Not conducive to retrofitting, load cell systems must be part of the vessel support and piping de- sign. Also, the specific gravity of the liquid cargo must be known to calibrate the system. Load cells cost approximately $10,000.
Similar to using a load cell, the amount of fill can be determined by weight. Tanker trucks can be weighed empty and then weighed full. A gallon es- timate can be made by subtracting the before weight from the after weight and using a one-pound-per- gallon conversion. This can be done with traditional truck scales or portable truck scales.
Ultrasonic Level Transmitters Ultrasonic level sensors measure the time re-
quired for a sound wave to travel from the emitter to the object’s surface and return to the detector (Figure 7). Then the information is sent to a receiv- er located in the cab of the truck. By using sound waves, the ultrasonic level sensors are not subject to deterioration due to corrosivity, viscosity, or being coated or scaled by liquids as would a float gauge or sight tube. Liquids with foam, heavy va- por or turbulence do not work well with ultrasonic level sensors since those characteristics can absorb and/or deflect away a substantial portion of the re- turn signal (Flowline, 2016).
Guided Wave Radar First used in the early 1990s for measuring the
level of liquids, guided wave radar level sensors uti- lize a continuously suspended cable or rod (wave guide) inside the cargo tank. Guided wave radar may also be known as micro-impulse radar.
Guided wave radar level sensors operate by gen- erating electromagnetic energy of approximately 1 GHz, which is at the low end of what is consid- ered by RF engineering to be microwaves. The radar energy pulses are guided toward the surface of the liquid through a suspended cable or rod that runs the length of the desired measuring range. Using the re- flected radar pulses and time-of-flight, guided wave radar units measure the empty space (Lewis, 2012).
Costs & Benefits The expenditure to fit a cargo tanker with a fill-
level gauge is offset by the safety of keeping per- sonnel on the ground, away from noxious and toxic contaminants, and possible injury. Fluids need not be toxic to create a hazard. Overfilling can create slippery surfaces and cause exposure to contami- nants, while spills that feed insects and vermin can spread disease at food plants.
OSHA (2016) states that by implementing an ef- fective safety and health management system, em- ployers may expect to significantly reduce injuries and illnesses and thus reduce the associated costs. ASSE (2002) states, “There is a direct positive cor- relation between investment in safety, health and environmental performance and its subsequent re- turn on investment.” Employers can also benefit in avoiding costly litigation. Between 2013 and 2015, of the nine work injury lawsuits reported by North Carolina Lawyers Weekly (2016), the average set- tlement reached was $1.6 million.
Another incentive to protect workers is the mem- orandum of understanding (MOU) between the Department of Justice (DOJ) and OSHA. The MOU moves the OSH Act into DOJ’s Environment and Natural Resource Division and that division’s Envi- ronmental Crimes Section. The U.S. Attorney’s of- fices works with OSHA to investigate and prosecute worker endangerment violations (Smith, 2015). Not only could an incident be a financial cost to a com-
Figure 5
Float Gauge Float gauge
Fill-level indicators
Figure 6
Load Cell
Load cell
Figure 7
Ultrasonic Level Transmitter
Ultrasonic level transmitter
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pany, it could also mean criminal charges for an owner. OSHA Administrator David Michaels notes that employers now face prison terms of 25 years instead of 6 months if convicted of crimes that con- tribute to employee fatalities.
Smith (2015) notes that one firm’s owner was charged in June 2015 with four counts of making false statements, one count of obstruction of justice and one count of willfully violating an OSHA regu- lation causing death to an employee. He pleaded guilty to all charges and faces a maximum sentence of 25 years in prison, 3 years of supervised release, $1.5 million in fines and a $510 special assessment for the criminal conviction.
The cost for installing gauges on tank trucks range from approximately $40 for sight eyes and sight tubes to about $10,000 for load level gauges (Table 1). Even the $10,000 more sophisticated gauges are substan- tially less than the cost for litigated incidents.
DOT Guidance Following are details of the requirements under
DOT for which gauges are required. Using cargo tankers for bulk transport presents hazards to per- sonnel while loading and unloading, including ex- posure to confined spaces and falling, among other risks. Bulk packaging is defined by DOT in 49 CFR 171.8 (transportation regulations) as a packaging, other than a vessel or a barge, including a transport vehicle or freight container, in which hazardous materials are loaded with no intermediate form of containment. Defined by volume, it has:
1) maximum capacity greater than 450 L (119 gallons) as a receptacle for a liquid;
2) maximum net mass greater than 400 kg (882 lb) and a maximum capacity greater than 450 L (119 gallons) as a receptacle for a solid; or
3) water capacity greater than 454 kg (1,000 lb) as a receptacle for a gas.
Cargo tankers have manufacturing designs, gauges and loading procedures specified by DOT regulations in 49 CFR as well as American Society of Mechanical Engineers’ technical documents and other consensus standards. Tank specifications are given based on the material being transported. Some cargo tank trucks are not required by DOT to have fill-level gauges. Typi- cally, these vehicles haul nonhazardous materials and even though the cargo may be considered nonhazard- ous, the process of loading, unloading and hauling with a cargo tanker presents hazards. As noted in the case studies, one hazard is falling from the top of the cargo tanker. Eliminating the need to be on top of the cargo tanker reduces this risk and improves worker safety. For the type of tanker that DOT specifies for a specific material, fill-level gauge specifications for the different
type of cargo tanks also depend on the type of mate- rial transported. Fill-level gauges offer the opportunity to keep workers on the ground and should be used re- gardless of regulatory mandates to employ them.
The following discussion and example explain the sequential steps needed to determine the type of tanker and fill gauge necessary for DOT-defined haz- ardous materials. The type of tanker and gauge that can be used is listed in the hazardous materials table in 49 CFR 172.101. The bulk transport column (8C) of that table lists the type of cargo tanker that can be used for transport, with the three digits listed desig- nating the appropriate section of part 173 (Figure 8).
Once the type of cargo tanker that can be used is de- termined, then the specifications of the gauge needed can be found under the standards for that type of tank- er. As an example, hexafluoropropylene compressed or refrigerant gas R 1216, the standards listed for bulk transport are 49 CFR 173.314 and 173.315. The latter lists an MC-331-type cargo tanker, which is primarily for transportation of compressed gases.
Next, the type of gauge must be determined for that type of cargo tanker. A search of the trans- portation code gives 49 CFR 178.337-14, Gaug- ing Devices, and addresses the requirements. That subchapter references 49 CFR 173.315(h), which is a listing for the different compressed gases and the gauging device permitted for filling purposes.
For an MC 338, which is an insulated cargo tank motor vehicle, the DOT specification in 49 CFR 178.338-14 for gauging devices requires that the tanker have an accurate fixed-length dip tube, fixed trycock line or differential pressure liquid level gauge that indicates the maximum permitted level, which is 2% outage below the inlet of the pressure control valve or pressure relief valve and with a de- sign pressure at least that of the tank for the prima- ry control for filling. The standard requires that the gauge be designed and installed to accurately indi- cate the maximum filling level at the point midway of the tank both longitudinally and laterally.
Section 178.345 includes the general design and construction requirements applicable to specifica- tion DOT 406, DOT 407 and DOT 412 cargo tank motor vehicles. Section 178.345-12 specifies for gauging devices that:
Each cargo tank, except a cargo tank intended to be filled by weight, must be equipped with a gauging device that indicates the maximum per- mitted liquid level to within 0.5% of the nominal capacity as measured by volume or liquid level. Gauge glasses are not permitted.
A gauge glass is a glass or plastic tube for mea- suring liquid level in a tank or pressure vessel, usu- ally by direct sight (Tomsic & Hodder, 2000).
Figure 8: Example using DOT hazard-
ous materials table (excerpt). For hexafluoropropyl- ene compressed or refrigerant gas
R 1216, 49 CFR 173.314 or 49 CFR 173.315 bulk cargo
tanker standards would apply.
Figure 8
Example Using DOT Hazardous Materials Table
Symbols
Hazardous materials descriptions and proper shipping names
Hazard class or Division
Identification Numbers PG
Label Codes
Special provisions (§172.102)
(8) (9) (10) Vessel stowage
Packaging (§173.***)
Quantity limitations (see §§173.27 and 175.75)
Location Other Exceptions Non- bulk Bulk
Passenger aircraft/rail
Cargo aircraft only
(1) (2) (3) (4) (5) (6) (7) (8A) (8B) (8C) (9A) (9B) (10A) (10B) Hexafluoropropylene
compressed or Refrigerant gas R 1216
2.2 UN1858 2.2 T50 306 304 314, 315
75 kg 150 kg A
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Conclusion Cargo tank owners/operators should install
gauges to keep workers grounded, whether or not doing so is mandated by DOT or other regulations. Not only do gauges and other fill-level devices keep workers safe, but they also decrease the cost associ- ated with injuries while delivering a positive return on investment. The type of gauge to use may be in part a financial decision but it should also be based on the type of load to be transported. Gauge suppli- ers can provide selection guidance as well as advice on the efficacy of the fit between the cargo and the gauge or sensor. Another source of feedback is firms that use the gauge with a similar cargo. PS
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Fill-level gauges offer the opportu- nity to keep workers on the ground and should be used regardless of regulatory mandates to employ them.
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