Question: I was trying to check a microwave diode for proper bias voltage. I had my meter on diode check range but the readings that I was getting didn't seem right. It seemed like it worked fine on a standard diode. What could be the problem?
Answer: It's not really a problem. You need to get a diode booster test lead set (ATL60) to break down the much higher bias voltage that exists within microwave diodes. The voltage needed may be as much as 10 time that needed for a standard diode.

Question: My meter display often times reads "OUCH" or "OFL". Is this normal? What does this mean?
Answer: These displays are shown at different times for different reasons. Here are a few of those reasons: You don't have your thermocouple inserted and you are on the the range selection, you are on the resistance range and aren't connected to a circuit. You are locked into a range and are exceeding the maximum value allowed on that range. You may have a blown fuse if you are on the amps range.

Question: Why won't my clamp-on tester measure current with the test lead set?
Answer: The primary purpose in the design of a clamp-on tester is one that enables the user to safely take current readings on devices that operate on 10 amps or more. Below 10 amps, most of our multimeters have the capability to measure below 10 amps safely. We also have in our clamp-on line the ACM6000 mini-clamp, which will measure down to 10 milliamps with great accuracy.

Question: Can I use a clamp-on current attachment with the DL250 so that I will be able to measure DC Amps?
Answer:Yes you may. As with any of our attachments or adapters, you may interchange components between meters. The input impedance must match (its almost always 10 megaohms) and the meter must have the proper ranges and resolutions (its almost always DC millivolts).

Question: I can't get my clamp-on tester to give me a voltage reading. I've got it hooked up correctly too?
Answer: Testing for voltage when using a clamp-on tester always requires the use of a set of test leads

Question: When I wrap my amp-clamp around an appliance cord that is in use, shouldn't I get some kind of a reading?
Answer: No. An appliance cord is made up of 2 or 3 different wires. The result of the measurement will be zero, the opposing fields in each of the wires will effectively cancel each other out. To take this type of measurement simply wrap around only the hot wire. You could use our ALS1 line splitter to make the task easier.

Question: What range on the selector do I need to be on measuring DC amps with the ACM6100?
Answer: DC millivolts (1 amp = 1 millivolt)

Question: The DL235 has a "soft mode". What is this used for?
Answer: The soft mode changes the rate that the meter displays the reading on the screen. It is in effect the same as a running average. The meter will display the average of the samples that it took over a 3 second time frame. This is effective in "smoothing" the reading out on a rapidly changing signal.

Question: On the DL235, what is the 'crest' mode used for?
Answer: The crest mode will display the highest reading of a half wave of a sinusoidal waveform. This is only for use on the AC Amps function. This is useful in determining if the current flow is linear, that is without distortion. The more types of electronic equipment that are in use at one place at one time, the more chance that the supply voltage is distorted and in turn affects the current flow in devices that are using this supply voltage. When harmonic distortion is present in the supply voltage it can have several side effects. Some can be very costly to repair and damaging to equipment. The normal Crest Factor is 1.414 for linear loads. That means the Crest reading should equal the RMS reading times 1.414. Readings other than that mean a nonlinear current flow.

Question: The amperage on my DL235 will not zero on either AC or DC. Is the unit defective?
Answer: The DC Amp range can be reset to zero by holding the "hold" button down for three seconds, the meter should beep three ties and the display should go to zero or less that .20 amps. Some minor fluctuation is normal since the clamp is literally an antenna that will pick up an EMI or RFI in the area. The AC amp range is not adjustable. However it is normal for the reading to be around .20 or less. This is within the accuracy range of the meter. In most cases the fluctuations that you see when there is nothing in the jaws of the clamp will go away as soon as a signal is present.

Question: How come I cannot get Hz reading out of the meter? I have the test lead connected to the meter and the circuit.
Answer: Actually the hertz is read through the clamp jaws. Note that there must be enough current through the jaws to get an accurate amperage reading before a frequency reading can be read by the meter.

Question: What are the maximum AC or DC amps that the DL235 can measure?
Answer: 800 amps AC or DC

Question: I have a fast changing voltage and the display is fluctuating too fast to read, what should I do?"
Answer: Use the "soft mode" feature (takes 3 second samples).

Question: Can I detect the presence of "line harmonics" with a DL235?
Answer: Yes. Using Crest Mode harmonics may be detected (refer to user's guide for more information).

Question: How do you zero the DC amperage range?
Answer: Depress the data hold button for three seconds.

Question: Can I monitor frequency of a wall outlet?
Answer: Yes. Use the amp clamp jaws and select "Hz" (note: isolate the hot power wire in the line cord).

Question:How do I stop DL235 auto power shut off?
Answer: Push the on button twice.

Question: What is the warranty?
Answer: 5 year limited warranty.

Question: I need to measure a length of one gauge wire but there is no position for it on my meter on my CLM100.
Answer: That range was not included in the range selector. To measure the sizes that are not on the selector there is a conversion chart available. To obtain a copy of this chart contact UEi Technical Resources at (800) 547-5740.

Question: I get erratic readings from the CLM100 when I measure known lengths of wire. What am I doing wrong?
Answer: The most common mistake is not getting the leads fully inserted in the meter. Another possibility is the connection at the wire is not clean. Be sure to clean the wire with the supplied abrasice pad. Another possible cause is the meter and wire are not at the same temperature. It is important to allow the meter to reach the same temperature as the wire before attampting to measure the wire.

Question: Is there a method to test whether or not my CO detector is working?
Answer: Actually the best method, when in doubt, is to expose the detector to a known level of gas, then to see if the detector matches your gas concentration. When lives and personal safety are on the line, there isn't any room for guesswork.

Question: I have a DM383 and a ACO100. How do I set the meter up to read CO?
Answer: This is a good and common combination. The first step is to connect the ACO100 to the meter with the switch on the ACO turned off. Set the DM383 to the DCV 20 scale and turn the meter on. The reading on the meter is the relative condition of the battery in the ACO100. IF the level drops below 4.5V, replace the battery. This is an important step since the battery has a profound affect on the accuracy of the monitor. Next turn the switch on the ACO100 on and set the meter on the 2V scale. Once the reading has stabilized set the reading on the meter to read ".000" by turning the screw in the hole marked "zero". Be sure to perform this in fresh air. Now the reading that is on the meter is the amount of CO in the area you are in . A reading of ".009" is 9 PPM of CO.

Question: When I place the ACO100 in the flue of my furnace the meter gives me very erratic readings, sometimes even a '-' reading. What is going on?
Answer: The ACO series is not designed for the temperature or the humidity that is present in flue gases. It was designed for indoor air quality testing only. If you need to test flue gases you will need a dedicated combustion analyzer or the SGA91. The SGA91 is designed to test both flue gases and also pinpoint sources of carbon monoxide. The pump in the unit allows for very accurate testing of CO and is a great help in finding leaks.

Question: My combustion analyzer will give me an efficiency reading in 'net' or in 'gross', what does that mean and which is the right choice for me?
Answer: The term efficiency means the amount of energy in the fuel used that is converted to heat. Efficiency = 100% - losses. Net efficiency uses the net calorific value of the fuel and assumes that the latent heat of vaporization is not lost up the flue with the exhaust. For natural gas the reading can be as much as 11% higher that the Gross figure. Net efficiency is used in France and Germany, not usually in the USA.. Gross efficiency uses the gross calorific value of the fuel and assumes that the latent heat is lost up the flue with the exhaust. This is the most common figure in use in the USA.

Question: What is 'latent heat'?
Answer: Latent heat is the heat required to turn water at 100 degrees C into steam at 100 degrees C. (The change in state from liquid to gas without a rise in temperature.)

Question: I set the contrast on my Quintox handset too light and now I cannot see the screen, how do I reset the contrast to be able to read it without seeing it?
Answer: If the display is too light to read, first attempt to reset by pressing the "down" key on and off. This should bring the screen back dark enough to read. You must press the key repeatedly since holding the key down will only step the contrast one step at a time no matter how long you hold it down. Try to unplug the handset cable briefly, then reattach. If you still cannot get the screen to display, call the tech department and they will step you through the process.

Question: How often do I need to have my combustion analyzer re calibrated?
Answer: You should have the unit recalibrated once a year. It is best to send it during the summer months to have this performed since the unit is not usually in use as much. Also since repair demand is lower this time of year, the turn around time in the shop is usually shorter. If you follow this advice you analyzer will be ready for you when you need it.

Question: We have a 4 gas analyzer and work 5 gas capabilities. Will this instrument work?
Answer: Yes. Along with CO, HC, CO2, and O2 this is the "5th gas" (which is required on many IM240 checks).

The term "millivolts" is most often used as a matter of verbal and marketing convenience. It refers to 1/1000th of a volt. If you select the 2-volt or 4-volt position (or let your meter do it for you if your meter is autoranging), you will be able to measure 2000 or 4000 millivolts. In these situations you will have to ignore the decimal. For example, 750 millivolts will be seen as 0.750 volts.