Medical Meter Frequently Asked Questions
General Questions
How often should my meter be calibrated?
The meter should be checked for accuracy daily and calibrated as needed. A full calibration should be performed periodically (monthly is suggested, but it is up to the user) to ensure proper function of all parameters of the meter. It is important that the user periodically perform a full calibration on the pH circuit (using the 4.0 and 10.0 pH buffers) to ensure that the pH functions properly. Many customers check their meters using only the 7.0 pH buffer. The problem with this is that if the pH sensor is damaged (say by dropping the meter) it may read only 7.0, no matter what it is exposed to. Exposing and calibrating it with the 4.0 and 10.0 buffers will ensure that the pH functions properly.
How often should my meter be rinsed?
The Test Instrument User's Guide states that the meter should be rinsed after it is used. The interpretation of this is left up to the user. It is not intended to mean, however, that the meter needs to be rinsed after each and every time they take a measurement. It simply means to rinse the meter when the user is done using it, such as at the end of a shift, or when they are done checking their machines. At a minimum, it should be done at the end of a shift.
How should my meter be stored?
The Mesa NEO-CARE Cell Cleaning Solution is ideal for pHoenix, HYDRA, and NEO-STAT+ meters. To clean, rinse the meter thoroughly by filling the syringe and expelling NEO-CARE slowly three times. After the third time, expel the NEO-CARE from the meter, disconnect the meter from the NEO-CARE and draw the syringe back halfway pulling air into the cell and then cap the sample port. The meter can then be stored like this, with the port capped to prevent the residual NEO-CARE in the cell and syringe from drying out. NEVER store your meter with dialysate, bleach, or RO water in the cell.
How often should the syringe be replaced?
The Test Instrument User's Guide states that the typical life of the syringe is 6-9 months, depending on use. This is just an estimate, not a guarantee. When the syringe becomes difficult to pull, or it starts leaking, it is time to replace it. The syringe can be replaced by the user.
How often should the luers be replaced?
If the luer becomes visibly worn, or damaged, or cracks and/or breaks, replace it. The luer(s) can be replaced by the user. It is important to instruct the user to be sure to expel all of the fluid from the meter prior to removing the luer(s) to prevent fluid from getting into the meter.
My pH doesn’t function properly, what should I do?
1. “My meter just shows a dash.” Many times this symptom can be ‘fixed’ simply by having the user reset the factory defaults. Because of the way the pH calibrates, it is actually possible to get it so far out of calibration that it can’t be calibrated. That is why the option for resetting the factory defaults was included. Refer to the calibration guide for instructions on resetting the factory defaults. *NOTE: The meter must be fully recalibrated (except for temperature) if the defaults are reset.
2. “My pH drifts, I calibrate it and go to use it and it has drifted (up or down).” This is a typical symptom of a worn or defective pH Reference. If it has been a while since they have had the meter in for service, then it is probably just a depleted reference. If it is a new build or was just in for service, then it may have a defective reference or another problem.
3. “My pH reads 7.0 no matter what I do, and I can’t calibrate the 4.0 or 10.0.” This is a typical symptom of a damaged or broken pH sensor. The meter must be sent in for service/repair.
How often should the pH reference be replaced?
When the pH becomes unstable, or drifts significantly after calibrating the meter, the pH reference is probably depleted and the meter needs to be sent in for service/repair.
My conductivity reading says ‘Lo’ or is very erratic.
There are a few things that can cause this symptom. The most common is that the meter is ‘sucking air’, or has air bubbles in the measurement cell. The best way to dislodge air bubbles from the meter is to give a hard, rapid pull on the syringe and then flush it back and forth rapidly a couple of times. If the symptom still persists, then air may be being draw into the meter along with the sample. This could be from a cracked luer or a leaking check valve on the Tri-Station.
If it has been determined that there is no air being drawn into the meter and the symptom still persists, then it is probable that the measurement cell is damaged. The meter needs to be sent in for service/repair.
My meter didn’t show ‘C1-C2’ (‘CAL’) when calibrated.
The ‘C1-C2’ (‘CAL’) that is shown on the screen during the calibration process has no meaning other than to indicate to the user that the new calibration information is being stored into the meter’s memory. If the user enters the calibration mode (either level 1 or level 2) and then ends up not changing anything (not ‘calibrating’ the meter because it didn’t need it) the meter will NOT display ‘C1-C2’ (‘CAL’) because there was no ‘new’ calibration information to be stored. This fact is not in any of our literature.
Why does my meter only show dashes when I turn it on?
This is generally caused from a problem with the temperature circuit. If the Temperature reading is out of the specified operating range, or if it reads ‘HI’ or ‘Lo’, the pH and conductivity readings will only show dashes. The meter needs to be sent in for service/repair.
Note: Occasionally the customer may have their Tri-Station in a back room where the ambient room temp is very low, or they may have it positioned next to an outside wall. This could cause the temperature of their standard solutions to be too cold and out of the specified range for the pHoenix Meter. This happens mostly in the winter months. Have the customer move their Tri-Station to a warmer location.
Why do I have to use the EVEREADY 522 battery?
The physical size of the battery is smaller than many of the batteries available. The case of the meter was designed using this battery. Because of this, many other batteries with larger cases (Duracell, for instance) will not fit properly and may interfere with the case closing and sealing properly. There are other batteries available with similar dimensions to the EVEREADY 522. It is ok to use these as well. Mesa does not have a ‘list’ of acceptable batteries. The user must compare the sizes of the batteries and use the alternate battery at their own risk.
How should I clean my meter?
Refer to cleaning instructions in the Test Instrument User's Guide, page 7.
How often should I send my meter in to Mesa?
Mesa does not ‘specify’ how often a meter should be returned for service. This is left up to the discretion of the user. The meters are designed to be calibrated in the field and as long as the user is able to calibrate and use the meter reliably there is no reason for them to return it to Mesa for service. We at most will ‘suggest’ that they return it annually, but even beyond that the user should be instructed to follow whatever their own SOP (Standard Operating Procedure) states. Their SOP should be in compliance with the rules and regulations of their state, and any ‘suggestions’ from Mesa cannot override any said rules and regulations.
How do I send in my meter in for service or calibration?
Fill out a service order form which can be found HERE. On the form include the following information. Ship To Address, Bill To Address, P.O. #, Contact Information, Return Shipping Instructions, and a detailed description of the symptoms you are experiencing or the services requested. Pack the meter well and ship it to Mesa Labs, attn: Medical Service.
What is the shelf life of an un-opened bottle of solution?
For Conductivity Solutions, 1 Year from date of manufacture.
For pH Buffer Solutions, 2 Years from date of manufacture.
(expiration date is indicated on the bottle.)
For Neo-Care, no expiration date.
What is the shelf life of an opened bottle of solution?
For Conductivity Solutions, 30 days from date of opening.
For pH Buffer Solutions, 90 days from date of opening.
For Neo-Care, no expiration date.
Where can I find MSDS information?
MSDS information can be found HERE.
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Frequently Asked Questions (NEO-2 Meter)
Is it necessary for me to send in my Neo-2 Meter along with my Temp/Condo probe?
If the question is regarding the annual calibration of the Meter/Probe, then yes, they should both be sent in. Otherwise the answer depends on the circumstances.
If the user has other Temp/Condo Probes that are operating normally when connected to the Neo-2 meter then that would indicate that the Probe in question could be sent in alone. If the same symptom is observed no matter which Probe is plugged into the meter, then the problem is in the Neo-2 Meter and both it and the Probe should be sent in. If there is no way for the user to verify proper function of the Neo-2 Meter then they should be advised to send it in along with the Probe because there are calibrations that need to be performed on the Neo-2 Meter as well as the Probe.
Does it matter what type of 9V bat. I use in the Neo-2?
No, there are no specifications on the type or brand of the 9V battery used in the Neo-2. Rechargeable batteries can be used also, but there is no charging circuit to charge them while they are installed in the Neo-2.
My meter turns on, but the display is blank (or very light).
The contrast may be out of adjustment. Follow these steps to try to readjust the contrast.
1. With the meter off, attach a Temp/Condo Probe to the meter.
2. Turn the meter on. There should be a series of ‘clicks’.
3. When the meter stops clicking, turn the knob 1 (one) click to the left (counter clock wise).
4. Push the knob 2 (two) times.
5. Turn the knob 1 (one) click to the left (counter clock wise).
6. Push the knob 1 (one) time. The meter should now be in the mode for adjusting the contrast. Turn the knob left or right until the desired contrast is achieved. Press and hold the knob to save the new contrast setting. If this process does not work, then the meter should be sent in for service.
A message indicating an internal clock error appears when the meter is turned on.
This message indicates that the internal clock has stopped working for some reason, usually a dead battery. This function is used for inserting a time and date into the Temp/Condo Probe whenever it is calibrated either by Mesa or by the user. It has no effect on any other part or function of the Meter, nor does it effect the calibration of the Meter or Probe. The user can continue to safely use their Meter and chose to have the symptom addressed during the Meter’s next routine service, or they can return it to Mesa for repair.
Is it necessary to use a Ground Shunt with my Neo-2?
No. Because of the difference in the Conductivity Cell designs between the Neo-1 and the Neo-2 it is not necessary to use a Ground Shunt with the Neo-2 Meter.
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Frequently Asked Questions (90XL Meter)
Is it necessary for me to send in my 90XL Meter along with my Temp/Condo Pod?
The Temp/Condo Pod (as well as the pH and Pressure Pods) for the 90XL operate independently from the Display. The Display is not actually a meter, it is just a display. There is nothing in the display that needs to be calibrated. The only reason that the user should need to send their Display to Mesa is if it is damaged or malfunctioning and in need of repair, or for a software upgrade.
Is it necessary to match a particular Pod with a particular Meter in order to maintain proper calibration?
No. All of the Pods are serviced and calibrated individually, apart from the display. This enables the user to be able to plug any Pod into any port of any functional display and obtain accurate readings.
My Display seems to be malfunctioning. Is there a way to ‘reset’ the 90XL Display?
Yes, by simply pressing all 4 buttons at once. This resets the micro-processor and turns the Display on. If the Display does not turn on with this process, the battery my be dead, ask the user if they have the AC Adapter plugged in to the Display. If it is plugged in and this process still does not restore normal function to the display, then there are other problems and the user should return the display to Mesa for service.
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