{"id":38229,"date":"2024-02-12T20:04:14","date_gmt":"2024-02-12T20:04:14","guid":{"rendered":"https:\/\/www.alicat.com\/?post_type=article&#038;p=38229"},"modified":"2026-02-03T20:48:04","modified_gmt":"2026-02-03T20:48:04","slug":"fehlersuche-bei-einem-alicat-gerat","status":"publish","type":"support","link":"https:\/\/www.alicat.com\/de\/support\/troubleshooting-an-alicat-device\/","title":{"rendered":"Fehlersuche bei einem Alicat-Ger\u00e4t"},"content":{"rendered":"\n[et_pb_section fb_built=&#8221;1&#8243; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_row _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_column type=&#8221;4_4&#8243; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_heading title=&#8221;Troubleshooting an Alicat device&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][\/et_pb_heading][et_pb_text _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<p>When your Alicat instrument isn\u2019t working as expected, we want to help identify and resolve the issues as quickly as possible. Fortunately, most problems can be fixed without having to return the device to the factory. This article covers common issues with Alicat devices and outlines solutions.<\/p>\n<h2>Resolving error codes<\/h2>\n<p>When an error occurs with your Alicat device, you will receive an error code. Here are common error codes and troubleshooting measures you can take to resolve the issue.<\/p>[\/et_pb_text][et_pb_accordion _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; toggle_font=&#8221;|700|||||||&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_accordion_item title=&#8221;ADC&#8221; open=&#8221;on&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<p>This error is indicative on an analog to digital conversion error.\u00a0Typically this will occur when there is an internal hardware issue. This is caused by the main board not being able to talk to the processor chip.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Unit must be sent into Alicat for repairs.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;MOV&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>This is an error indicating that the mass flow has gone over range of the device (128% of full scale). This also shows up if the setpoint is too far over the custom range of the device. Custom ranges increase accuracy by decreasing the full scale.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Reduce flow and recheck operating conditions.<\/span><\/li>\n<li><span style=\"color: #000000;\">Before using, verify readings on the device at atmospheric conditions<\/span><\/li>\n<li><span style=\"color: #000000;\">Compare these readings to a known state.<\/span><\/li>\n<li><span style=\"color: #000000;\">If unit has a custom down-scale range, and a higher range is desired, unit must be sent in for reconfiguration and re-calibration.<\/span><\/li>\n<li><span style=\"color: #000000;\">If sensor damage is suspected, check registers 8 and 10, and compare them to the values originally shipped on the device.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;OPL&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>The instantaneous (with no averaging) pressure has exceeded the designated over pressure limit. This causes the valve on the device to close.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">The setpoint on the device must be adjusted digitally or physically on the front screen.<\/span><\/li>\n<li><span style=\"color: #000000;\">A power cycle will also clear the OPL error.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;POV&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Similar to MOV and VOV, this error indicates that the pressure has gone over the specified range of the device (128% of full scale).<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Reduce pressure and recheck operating conditions.<\/span><\/li>\n<li><span style=\"color: #000000;\">Before using, verify readings on the device at atmospheric conditions<\/span><\/li>\n<li><span style=\"color: #000000;\">Compare these readings to a known state.<\/span><\/li>\n<li><span style=\"color: #000000;\">If sensor damage is suspected, check registers 8 and 10, and compare them to the values originally shipped on the device. You may also check the PSIA reading of your device at ambient conditions. If your value is non-reasonable number, you may have a damaged sensor.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;TOV&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>This error means the temperature is outside of the bounds specified within our devices. When the temperature is outside specified bounds, flow readings are no longer reliable. On older non-rechargeable battery units, this would happen roughly 10-60 minutes before the unit would lose all charge.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Check power supply output. If a power supply dips in voltage, the temperature readings are typically the first to show signs.<\/span>\n<ul>\n<li><span style=\"color: #000000;\">On older non-rechargeable battery units, this would happen roughly 10-60 minutes before the unit would lose all charge.<\/span><\/li>\n<\/ul>\n<\/li>\n<li><span style=\"color: #000000;\">Replace battery (older battery units)<\/span><\/li>\n<li><span style=\"color: #000000;\">Verify there is no sensor damage<\/span><\/li>\n<li><span style=\"color: #000000;\">Compare readings in a known atmospheric condition.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;VOV&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Similar to MOV and POV, this error indicates a volumetric flow reading that is outside the range of the device.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Reduce flow and recheck operating conditions.<\/span><\/li>\n<li><span style=\"color: #000000;\">Before using, verify readings on the device at atmospheric conditions<\/span><\/li>\n<li><span style=\"color: #000000;\">Compare these readings to a known state.<\/span><\/li>\n<li><span style=\"color: #000000;\">If sensor damage is suspected, check registers 8 and 10, and compare them to the values originally shipped on the device. You may also check the PSIA reading of your device at ambient conditions. If your value is non-reasonable number, you may have a damaged sensor.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][\/et_pb_accordion][et_pb_text _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<h2><\/h2>\n<h2>Power and communication issues<\/h2>\n<div class=\"su-spoiler su-spoiler-style-fancy su-spoiler-icon-chevron su-spoiler-closed\" data-scroll-offset=\"0\" data-anchor-in-url=\"no\">\n<div class=\"su-spoiler-title\" role=\"button\" tabindex=\"0\"><\/div>\n<\/div>[\/et_pb_text][et_pb_accordion _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; toggle_font=&#8221;|700|||||||&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_accordion_item title=&#8221;Display won&#8217;t turn on, or is dim\/weak&#8221; open=&#8221;on&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<ul>\n<li><span style=\"color: #000000;\">Check the power and ground connections to your instrument.<\/span><\/li>\n<li><span style=\"color: #000000;\">Check the display contrast settings by selecting\u00a0<strong>MENU &gt; ADV SETUP &gt; DISP SETUP &gt; LCD CONTRAST<\/strong>. The default contrast level set at the factory is 10.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Buttons on display do not respond and &#8216;LCK&#8217; appears on the screen&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Alicat devices come with a display locking option to prevent inadvertent changes to setpoints or settings. If the error code \u2018LCK\u2019 appears on the screen, your device display has been locked.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">If your device was manufactured with firmware version 6v or later, you can unlock the display by pressing\u00a0and holding the buttons located at the four corners of the display until \u2018LCK\u2019 disappears.<\/span><\/li>\n<li><span style=\"color: #000000;\">All devices equipped with our\u00a0<a href=\"https:\/\/www.alicat.com\/support\/communication-options-for-alicat-instruments\/\" style=\"color: #000000;\">standard serial communications<\/a>\u00a0can be unlocked by issuing the following serial command: [Unit ID]<strong>$$U<\/strong>&lt;CR&gt;. (Replace [Unit ID] with your device\u2019s single letter Unit ID.)<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Analog output indicates values lower than what appears on instrument display&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<div class=\"su-spoiler su-spoiler-style-fancy su-spoiler-icon-chevron\" data-scroll-offset=\"0\" data-anchor-in-url=\"no\">\n<div class=\"su-spoiler-content su-u-clearfix su-u-trim\">\n<p>Analog signal voltage degrades over long distances. You can minimize this effect by using wires with a heavier gauge, especially in the ground wire.<\/p>\n<\/div>\n<\/div>\n<div class=\"su-spoiler su-spoiler-style-fancy su-spoiler-icon-chevron su-spoiler-closed\" data-scroll-offset=\"0\" data-anchor-in-url=\"no\">\n<div class=\"su-spoiler-title\" role=\"button\" tabindex=\"0\"><\/div>\n<\/div>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Connecting an Alicat to a computer serially&#8221; _builder_version=&#8221;4.27.0&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Nearly all Alicat instruments are manufactured with digital serial communications. Follow the steps below to establish a connection to your Alicat from your Windows computer:<\/p>\n<ol>\n<li><a href=\"https:\/\/downloads.alicat.com\/software\/SerialTerminal.zip\">Download our Serial Terminal program.<\/a><\/li>\n<li>If you are connecting with a USB cable, <a href=\"https:\/\/www.alicat.com\/documentation\/software-drivers\/\">install the USB driver<\/a>. This creates a virtual COM port on your computer.<\/li>\n<li>Open your computer\u2019s Control Panel, and then open Device Manager.<\/li>\n<li>Under \u201cPorts (COM &amp; LPT)\u201d, find the COM port number that is connected to your Alicat. If you are using a USB cable, the virtual COM\u00a0port will be called \u201cUSB Serial Port (COM#)\u201d. Take note of the COM port number.<\/li>\n<li>Open the Serial Terminal program.<\/li>\n<li>Serial Terminal will ask for the COM port and baud rate. Enter the COM port you found above and the default baud rate of 19200.<\/li>\n<li>Type the single-letter Unit ID for your Alicat instrument, and press enter <strong>&lt;CR&gt;<\/strong>. If you do not know your device\u2019s Unit ID, you can find it by selecting\u00a0<strong>MENU &gt; ADV SETUP &gt; COMM SETUP<\/strong> on the display.<\/li>\n<li>If your computer returns a line of data after Step 7 above, you have successfully established serial communications.<\/li>\n<\/ol>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Computer cannot communicate with the Alicat over a serial connection&#8221; _builder_version=&#8221;4.25.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<ul>\n<li>Check that your unit is powered on and connected to your computer properly. See above instructions to connect your instrument.<\/li>\n<li>Be sure that the COM port on the computer to which the Alicat is connected is active. Open Device Manager to confirm that the COM port is visible.<\/li>\n<li>When connecting multiple devices to a single COM port (or virtual COM port if using USB), be sure to give each Alicat device a unique Unit ID. You can change the Unit ID by selecting\u00a0<strong>MENU &gt; ADV SETUP &gt; COMM SETUP &gt; UNIT ID.<\/strong><\/li>\n<li>Alicat\u2019s RS-232 output uses a 0-5 Vdc signal. See this document for details:\u00a0<a href=\"https:\/\/documents.alicat.com\/specifications\/Alicat_RS-232_Specs.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><strong>RS-232<\/strong>\u00a0Output Specifications<\/a>.<\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Computer cannot find BB3 or BB9 multi-drop breakout boxes&#8221; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<ul>\n\t<li><span>If your BB3 or BB9\u00a0<a href=\"https:\/\/www.alicat.com\/products\/accessories\/breakout-boxes\/\">multi-drop box<\/a>\u00a0is showing up under \u201cother\u201d in your device manager instead of \u201cPorts (COM &amp; LPT)\u201d, the most likely cause is a missing driver. While this should install automatically when plugging into your computer, occasionally security settings can prohibit it from installing. You can download and install the driver manually from our\u00a0<a href=\"https:\/\/www.alicat.com\/documentation\/software-drivers\/\">Software &amp; Drivers page<\/a>.<\/span><\/li>\n\t<li><span>If you are using a USB port with Windows 7 and receive the error, \u201cOne of the USB devices attached to this computer has malfunctioned and Windows does not recognize it\u201d, the USB port itself is not responding properly.\u00a0<a href=\"https:\/\/answers.microsoft.com\/en-us\/windows\/forum\/windows_7-hardware\/one-of-the-usb-devices-attached-to-your-computer\/b8a2fc66-5e58-48a3-9d3b-1db2858c3a9e\" target=\"_blank\" rel=\"noopener noreferrer\">Microsoft has released a solution on its forum.<\/a><\/span><\/li>\n\t<li><span>If you are using the 9-pin serial connection on your computer and your COM port does not appear in Device Manager, the COM port on the computer or the cable may have stopped functioning. Please try connecting to the computer using a different cable or different port (USB), and check Device Manager again.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][\/et_pb_accordion][et_pb_text _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<h2><\/h2>\n<h2>Incorrect flow readings<\/h2>\n<div class=\"su-spoiler su-spoiler-style-fancy su-spoiler-icon-chevron su-spoiler-closed\" data-scroll-offset=\"0\" data-anchor-in-url=\"no\">\n<div class=\"su-spoiler-title\" role=\"button\" tabindex=\"0\"><\/div>\n<\/div>[\/et_pb_text][et_pb_accordion _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; toggle_font=&#8221;|700|||||||&#8221; hover_enabled=&#8221;0&#8243; global_colors_info=&#8221;{}&#8221; sticky_enabled=&#8221;0&#8243;][et_pb_accordion_item title=&#8221;Negative flow readings&#8221; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;on&#8221;]<ul>\n\t<li><span><strong>If gas is flowing through your device<\/strong>, it may be flowing in the wrong direction. If you expect flow in both directions, you can ask for a bidirectional flow calibration during your instrument\u2019s annual recalibration.<\/span><\/li>\n\t<li><span><strong>Under conditions of no flow<\/strong>, a negative flow reading indicates that the meter was flowing when it was last tared. To correct this, tare your device.<\/span><\/li>\n\t<li><span><strong>If you have a low pressure drop flow meter<\/strong>\u00a0(<a href=\"https:\/\/www.alicat.com\/products\/gas-flow\/mass-flow-meter\/low-pressure-drop-mass-flow-meters\/\">Whisper<\/a>\u00a0or\u00a0<a href=\"https:\/\/www.alicat.com\/products\/calibrators\/fp-25-field-flow-calibrator-for-pm-air-samplers\/\">FP-25<\/a>) that is not connected to anything, the device may be reading a light breeze that is entering its outlet. Plug one end to see if the flow returns to 0.<\/span><\/li>\n<\/ul>\n<div class=\"link-with-icons-wrap m-b\"><a href=\"https:\/\/www.alicat.com\/support\/taring-auto-taring-tutorial\/\">Tutorial: Taring an Alicat device<\/a><\/div>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Changing flow reading units&#8221; _builder_version=&#8221;4.25.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Flow, pressure, and temperature readings can be displayed using a wide range of <a href=\"https:\/\/www.alicat.com\/documentation\/engineering-units\/\">engineering units<\/a>.<\/p>\n<div class=\"link-with-icons-wrap m-b\"><a href=\"https:\/\/www.alicat.com\/support\/changing-engineering-units-tutorial\/\">Tutorial: Changing engineering units<\/a><\/div>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Live flow readings won&#8217;t settle&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Alicat flow measurement is very fast, so your instrument can detect subtle variations in flow that may\u00a0go unnoticed by other flow instruments. If your pressure supply is variable or you are calibrating a pump that is oscillating, try the following to smooth out the reported flow readings:<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Increase the flow averaging time constant.<\/span><\/li>\n<li><span style=\"color: #000000;\">If you ordered your device with totalizer averaging (TOTAVG in your part number), reset your totalizer. The averaged flow rate updates in real time, so you can watch it until the value stops changing. If you have an\u00a0<a href=\"https:\/\/www.alicat.com\/products\/calibrators\/fp-25-field-flow-calibrator-for-pm-air-samplers\/\" style=\"color: #000000;\">FP-25<\/a>, you can record a single averaged flow reading over a specified amount of time by pressing\u00a0<strong>START AVG<\/strong>\u00a0from the instant screen.<\/span><\/li>\n<li><span style=\"color: #000000;\">It is also possible that you may have some small debris (such as shredded pieces of Teflon tape) stuck in the flow path. Inspect the inside of the upstream process port to ensure there is no debris.<\/span><\/li>\n<\/ul>\n<div class=\"link-with-icons-wrap m-b\"><a href=\"https:\/\/www.alicat.com\/support\/flow-and-pressure-averaging-tutorial\/\">Tutorial: Flow and pressure averaging<\/a><\/div>\n<div class=\"link-with-icons-wrap m-b\"><\/div>\n<div class=\"link-with-icons-wrap m-b\"><a href=\"https:\/\/www.alicat.com\/support\/totalizer-tutorial\/\">Tutorial: Using your totalizer<\/a><\/div>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Readings don&#8217;t change when flow changes&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p><strong>Scenario 1:<\/strong><\/p>\n<p>Flow readings that won\u2019t change regardless of actual flow usually indicate a damaged flow sensor. This is usually the result of exceeding the maximum allowable instantaneous differential pressure for your device (75 PSID for most instruments; 15 PSID for Whisper and FP-25).<\/p>\n<p>For meters, this may happen when an upstream solenoid valve suddenly snaps open to allow the high-pressure gas through the meter. For controllers, the valve usually protects the sensor from large pressure differentials. If the pressure changes suddenly, the valve may not have time to adjust and the sensor may be subjected to high pressure drops.<\/p>\n<p><em>Note: Sensor damage due to excessive differential pressure is not covered by Alicat\u2019s warranty.<\/em><\/p>\n<div class=\"link-with-icons-wrap m-b\"><a href=\"https:\/\/www.alicat.com\/contact\/\">Contact Alicat to discuss repair options<\/a><\/div>\n<p><strong>Scenario 2:<\/strong><\/p>\n<p>Alicat mass flow meters can be tared by grounding a specified pin (<a href=\"https:\/\/www.alicat.com\/technical-reference\/#pinouts\" target=\"_blank\" rel=\"noopener noreferrer\">pinout diagrams<\/a>). If this pin is continuously grounded, it will cause the flow reading to read 0 at all times.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Please check your electrical connections to ensure this pin is not grounded.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Readings jump to 0 at low flow rates&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Your flow instrument is equipped with a programmable deadband that is preset at the factory. Usually, the deadband preset is 0.5%, so any flow reading below this level displays as 0.<\/p>\n<ul>\n<li><span style=\"color: #000000;\">Reduce your deadband threshold by selecting\u00a0<strong>MENU &gt; ADV SETUP &gt; SENSOR SETUP &gt; ZERO BAND<\/strong>.<\/span><\/li>\n<\/ul>\n<p><em>Note:<\/em> The deadband threshold has no effect upon the serial data frame.<\/p>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Incorrect gas selected&#8221; _builder_version=&#8221;4.25.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<p>Alicat devices can be used to flow over 98 gases and gas mixes, but it is important to verify that the correct gas is selected prior to flowing. Having the wrong gas selected will not cause any damage to your device, but all\u00a0flow readings will be off by approximately the ratio of the viscosities of the two gases.<\/p>\n<p>This is an easy issue to fix. All you have to do is multiply the readings by the ratio of the selected gas viscosity to the desired gas viscosity. To prevent the problem from occurring again, update the gas selection in the <a href=\"https:\/\/www.alicat.com\/documentation\/gas-select-gas-list\/\">Gas Select\u2122 menu<\/a>.<\/p>\n<p><a href=\"https:\/\/www.alicat.com\/support\/correcting-flow-data-after-choosing-the-wrong-gas-in-gas-select\/\">For more details, check out this flow data correction tutorial<\/a><\/p>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Volumetric flow readings don&#8217;t match another flow calibrator&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<ul>\n<li><span style=\"color: #000000;\">If you are flowing dry gas, the\u00a0differences\u00a0in flow readings are likely the result of\u00a0<a href=\"https:\/\/www.alicat.com\/support\/what-is-pressure-drop\/\" style=\"color: #000000;\">pressure drop<\/a>. Every flow\u00a0meter has some amount of pressure drop, especially those that use\u00a0differential pressure as the measurement method. For example, volumetric flow readings taken with a standard Alicat flow meter may differ from those taken with one of our low pressure drop Whisper flow meters.<\/span><\/li>\n<li><span style=\"color: #000000;\">If you are using an Alicat flow instrument with a live humidity sensor (FP-25), you will see bigger differences in flow readings the higher the relative humidity or temperature is. This is because other flow meters do not account for the content of water vapor in the air (or gas), which physically changes how air flows.<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;Mass flow readings don&#8217;t match another flow calibrator&#8221; _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; open=&#8221;off&#8221;]<ul>\n<li><span style=\"color: #000000;\">Check the STP or NTP settings (<strong>MENU &gt; BASIC CONFIG &gt; STP\/NTP<\/strong>) to\u00a0ensure that your standard (or normal) temperature and pressure references\u00a0match those of your other flow calibrator.<\/span><\/li>\n<\/ul>\n<p><iframe title=\"Alicat Mass Flow Controller: How To - Change Standard Temperature and Pressure (STP)\" width=\"1080\" height=\"608\" src=\"https:\/\/www.youtube.com\/embed\/M-IJXoM707A?feature=oembed&rel=0\"  allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen><\/iframe><\/p>\n<ul>\n<li><span style=\"color: #000000;\">Ensure that both meters are configured to flow the gas you are currently flowing (<strong>MENU &gt; BASIC CONFIG &gt; GAS<\/strong>).<\/span><\/li>\n<\/ul>[\/et_pb_accordion_item][et_pb_accordion_item title=&#8221;BASIS device has inaccurate flow readings&#8221; open=&#8221;off&#8221; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; hover_enabled=&#8221;0&#8243; global_colors_info=&#8221;{}&#8221; sticky_enabled=&#8221;0&#8243;]<p><span style=\"color: #ff0000;\"><span style=\"color: #000000;\">In the scenario that your BASIS instrument begins displaying inaccurate flow readings it is recommended that you manually tare using <strong data-start=\"224\" data-end=\"249\">pure process gas only<\/strong>. <span data-teams=\"true\">The zero signal that is tared out is dependent on gas properties, any impurities that are present will cause measurement inaccuracy.\u00a0<\/span><\/span><\/span><\/p>\n<ul>\n<li><span style=\"color: #ff0000;\"><span style=\"color: #000000;\">Before taring, run pure process gas through the system for an extended period of time to ensure any residual gases or contaminants from previous operations are removed<\/span><\/span><span style=\"color: #ff0000;\"><span style=\"color: #000000;\"><\/span><\/span><\/li>\n<li>Once you are confident that the system is fully conditioned with pure process gas, proceed with the taring process. This ensures the mass flow meter zeroes accurately and reflects only the flow of the intended gas moving forward.<\/li>\n<\/ul>[\/et_pb_accordion_item][\/et_pb_accordion][et_pb_text _builder_version=&#8221;4.23.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<h2>Liquid ingress into a gas flow instrument<\/h2>\n<p>Gas flow controllers and meters are designed to flow only gases, but accidental liquid ingress into a gas flow device can happen in most environments.<\/p>\n<div class=\"link-with-icons-wrap m-b\"><strong><a href=\"https:\/\/www.alicat.com\/support\/liquid-in-a-gas-flow-instrument-faq\/\">What to do if liquid gets into a gas device<\/a><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<h2><\/h2>\n<div class=\"link-with-icons-wrap m-b\"><\/div>[\/et_pb_text][et_pb_text _builder_version=&#8221;4.26.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<h2><\/h2>\n<h2>Tuning issues<\/h2>\n<p>When an Alicat unit leaves the factory, the valve is configured to operate at certain standard conditions.\u00a0 Sometimes these valve characterization conditions do not match the actual operating conditions. When this happens, it is possible the device won\u2019t control with the speed or stability typical to an Alicat controller.<\/p>\n<p>Don\u2019t panic! With mainline Alicat controllers (your part number begins with MC or LC), it is possible to change gains in the control algorithm using the front panel or serial communication. More often than not, what seems to be a non-functional unit is just a controller configured for the incorrect application.<\/p>\n<h3 class=\"link-with-icons-wrap m-b\"><strong>Autotuning<\/strong><\/h3>\n<p class=\"link-with-icons-wrap m-b\"><strong><\/strong>For Alicat devices with part numbers beginning with MC or LC, and running firmware version 10v11 or higher, an autotune capability (labeled Optimize Control) is built-in to the firmware. You&#8217;ll find it from the home screen by choosing <strong>MENU &gt; SETUP &gt; CONTROL<\/strong>. If you see <strong>OPTIMIZE CONTROL <\/strong>on the menu, you can use autotune to optimize your control valve&#8217;s response to the current conditions. See your device&#8217;s <a href=\"https:\/\/www.alicat.com\/technical-reference\/\">user manual<\/a> for directions.<\/p>\n<p class=\"link-with-icons-wrap m-b\"><\/p>\n<h3 class=\"link-with-icons-wrap m-b\"><strong>Tuning manually<\/strong><\/h3>\n<div class=\"link-with-icons-wrap m-b\"><strong><\/strong><\/div>\n<div class=\"link-with-icons-wrap m-b\">\n<p class=\"link-with-icons-wrap m-b\">If you have an MC or LC instrument running firmware older than 10v11, you might check with our service department to see if an update is possible on your device&#8217;s chipset. Even if not, there is a manual option on most older devices.<\/p>\n<p><strong><a href=\"https:\/\/www.alicat.com\/support\/pid-tuning-pd-pdf-and-pd2i-tutorial\/\">View the PID\/valve tuning tutorial<\/a><\/strong><span style=\"font-size: 14px;\">\u00a0<\/span><\/p>\n<\/div>\n<h2><\/h2>\n<div class=\"link-with-icons-wrap m-b\"><\/div>[\/et_pb_text][et_pb_text _builder_version=&#8221;4.26.1&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<h2>Downloading device registers<\/h2>\n<p>When troubleshooting an Alicat device, it can be helpful to first download all of the device registers. An applications engineer can use these registers to help you isolate the problem and find a solution.<\/p>\n<div class=\"link-with-icons-wrap m-b\"><strong><a href=\"https:\/\/www.alicat.com\/support\/download-and-edit-register-settings-and-factory-restore-an-alicat-tutorial\/\">Device registers and factory restore tutorial<\/a><\/strong><\/div>[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]\n","protected":false},"featured_media":46458,"parent":0,"template":"","meta":{"_acf_changed":false,"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"1920","content-type":"","_searchwp_excluded":""},"categories":[],"class_list":["post-38229","support","type-support","status-publish","has-post-thumbnail","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v27.3 (Yoast SEO v27.3) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Troubleshooting an Alicat Device - Alicat Scientific<\/title>\n<meta name=\"description\" content=\"When your Alicat instrument isn\u2019t working as expected, we want to help identify and resolve the issues as quickly as possible. 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