Web Exclusive! Insight into Instrument Repair
When you’re the one measuring the world, instrument repair is inevitable as it is for every surveyor. Since surveyors are so dependent on their instruments, the efficiency and quality of the repair process must meet high standards. Specifics including timing, cost and reliability of the repair person carry a heavy weight. Surveyors often find themselves trying to fix problems themselves. But since 43 percent of the respondents of a POB Online Point of View poll taken in May indicated that they don’t know how to repair their instruments, it is imperative to know of a reliable instrument repair shop. Once you get the equipment there, you, like any other consumer, want satisfactory service and turnaround. Is this the general experience?
When It’s Time to Take It InMore than 50 percent of POB Online Point of View respondents (138 total) said they have their instruments repaired only when needed. A small four percent head out to the repair shop regularly every six months, and 37 percent have them repaired annually.
“Sending instruments in for repair or calibration on a regular basis provides a basis for knowing your crews have the right tools to do their job,” says Ernest Warner, a professional land surveyor in private practice. “How often do you have your car serviced? Probably no one will sue you if your car breaks down, but if you stake infrastructure in error due to your instrument being out of calibration, watch out.”
Some surveyors are more comfortable sending their conventional units back to the factory instead of looking to repair shops. However, factory-backed repairs are often not as convenient since some factories are states away from the surveyor in need. The bottom line is that instruments need minor fixes and repairs all the time if you want to stay productive.
“With modern instruments becoming more electronic and less mechanical it is getting increasingly difficult to do calibration or repair work onsite. All of our equipment is fully robotic. We’re fortunate enough to have an extra unit so rotating equipment for service needs doesn’t interrupt our production. I consider the extra expense for service of robotic equipment is offset by the added production rates gained by their use,” says Tony Ware, a survey manager in Dallas, Texas.
Satisfaction Guaranteed?Sure, you may be able to “fix” your own instrument on occasion, which is great during an in-field emergency, but do you know all the ins and outs of complete instrument repair? Will you seal the equipment to protect it from water and dust, for instance?
“I have a True Plumb pole adjustment outfit from Chrisnik [Inc., Ross, Ohio] and an Optical Plummet Tribrach Adjustment outfit, both purchased from LO Ink [Specialties, Kennebunkport, Maine],” says Sam Clemons, LS, owner of Clemons Surveying in Jasper, Tenn. “We can run some checks and adjustments on our total station, but if we even think it is messed up or needs adjustment (usually some kind of blow or drop knocks it out), we take it to Hayes Instruments for adjustment.”
Hayes Instrument of Shelbyville, Tenn., a 30-year-old firm regarded highly by surveyors, sees a lot of instruments in its daily routine. Total stations are the instruments fixed the most at Hayes for two reasons: they are the instruments most sold and most used. John Boyd, president of Boyd Instrument & Supply Co. Inc., of Horsham, Pa., experiences the same when it comes to the most frequent repairs.
“For contractors, it’s levels; for surveyors it’s total stations,” Boyd says. “Mainly because surveyors aren’t using levels as much, so the more you use a total station, the more fixing it needs.”
There aren’t any instruments surveyors can fix themselves, according to Hayes President/Owner Eddie Clanton. Minor adjustments can be done, he says, such as adjusting the optical plummet or the level vial, or checking the EDM on a baseline.
“Ninety-nine percent of the time they’ll have to bring it in,” Clanton says.
Boyd agrees that no instruments can be fully repaired by the average surveyor. Basic, simple onsite calibrations and checks can be done onsite, though, Boyd says. His shop now carries a patent-pending prism pole adjustment tool. Coined as the “Prism Pole Field Adjuster,” it can be used conveniently onsite.
“There’s no reason to drive for an hour for something like that when you can fix it in the field,” Boyd says. Boyd’s father, an instrument maker since 1945, designed the tool, which sells for $39.95. Boyd says his office had presold quite a few before the tool was even manufactured.
Only four percent of our poll respondents know how to repair their instruments on their own. Fifty-three (53) percent do know how to repair at least some of their instruments. But if you’re in that “99 percent of the time” category and you don’t know how to fix your instrument, a qualified technician is required. Almost 60 percent said that the technicians at their repair shops were qualified to perform the work.
Service SatisfactionWhen you are in need of repairing your instrument quickly because the project completion date is rapidly approaching, nothing matters more than quick turnaround.
When surveyors find themselves lugging their equipment to Hayes, they can expect to pick it up in two to three days for simple maintenance and calibrations, and 10 days minimum for repairs, Clanton says. Boyd Instrument & Supply Co. promises a 10 working day turnaround as well.
Our recent poll indicated that surveyors usually experience a fast turnaround time. Usually. But, what about the times when the repair has no promise of quick turnaround? What about the times when the parts have to be ordered, and they won’t be in soon enough? Do you get a loaner, borrow from a nearby firm, buy another unit for the interim? Fifteen (15) percent said that the shops they used provided loaners, 45 percent said they provided both loaners and rentals and 26 percent said they provided rentals only. The remaining 15 percent said they provided neither.
If you are given a loaner or rental, test it first or get one that is equivalent to the one you’re having repaired. Have the instrument checked and calibrated before you walk out the door.
Should Hayes need to keep instruments longer than its 10-day minimum, customers are offered loaners or rentals. “[We offer] both,” Clanton says. “It depends on the situation. If they are new customers, we’ll probably offer them rentals. Regular customers who can be trusted can take rentals.” Clanton also said all rentals are calibrated and checked before being handed over.
John Boyd of Boyd Instrument & Supply Co. Inc., says many more loaners are provided to customers than rentals, especially since some small surveying firms may be turning in their only total station for repair. Boyd provides them with a loaner compatible to the one turned in for repair, completely calibrated and checked. Rentals run from $200 to $500.
Hayes provides a 120-day warranty on parts and workmanship unless the equipment is mishandled, which is defined as equipment that has been dropped or misused.
Instruments Most Repaired and WhySome common instrument problems:
John Boyd of Boyd Instruments & Supply Co. Inc., highlights three main instruments and easy “fixes” in a seminar called Surveying Equipment Adjustments he has given at state society conferences: prism poles, automatic levels and total stations.
Broken down, some of the common problems and fixes are:
Common problem: level vial out of adjustment
Causes: Adjustment is out; worn or striped threads in vial housing and/or screw; worn or missing rocker; housing is loose; vial is defective
Trouble-shooting: Make sure the housing is tight on the pole. Make sure that vial is not loose is the housing. Press on the dot with a dull pencil; the bubble should not move.
Common problem: circular level vial is off
Causes: The vial is out of adjustment, the tension of leveling screws is too tight, the center is loose, the vial is loose in housing or the vial is defective.
Common problem: The level line is off.
Causes: The cross wires are out of adjustment, there is a loose objective lens, the compensator is sticking.
Common problem: The level vial is out of adjustment.
Causes: The level vials are out of adjustment, are loose in housing, are defective, the center is bent or loose, or there is too tight of tension of leveling screws. Plate level vial:
Common problem: The optical plummet is out of adjustment.
Causes: Out of adjustment, housing is loose.
Common problem: Collimation is out of adjustment.
Causes: The wires are out of adjustment.
Zero set procedure:
Common Problem: Distance measurements are not possible, weak, incorrect, or not to maximum specifications.
Causes: The prism constant is wrong, instrument constant is wrong, EDM beam is out of alignment, LED is defective or weak, optical fiber is broken.
Normally, the instrument constant does not have any discrepancy. However, it is recommended when measuring the instrument constant to compare it with an accurately measured distance at a place where the precision is specifically indicated once every six months.
So if you need your instrument calibrated, consider a "quick-fix" in the field. But if the repair is beyond your knowledge, trust it to the experts.