# On Call Glucometers & Test Strips Complete Guide: Plus, Extra, GK Dual, Compatibility & Troubleshooting **By Microsidd India** · 2026-09-24 **On Call** is a blood glucose monitoring product family from **ACON Laboratories** with several different meter and test-strip systems. At Microsidd, the main On Call systems currently relevant to customers include **On Call Plus**, **On Call Extra** and **On Call GK Dual**. Although these products share the On Call brand name, they should not be treated as one interchangeable system. The meter model determines which test strips, setup procedure and troubleshooting instructions should be followed. This guide explains the differences between the major On Call systems, test-strip compatibility, common meter features, pack options, error-code troubleshooting, storage considerations and how to choose the correct product. If you already know what you need, visit our [**On Call Glucometers & Test Strips Collection**](/collections/on-call-glucometer-test-strips) . * * * ## What Is an On Call Glucometer? On Call blood glucose monitoring systems are manufactured by **ACON Laboratories**. Different On Call meter families have been developed with different strip technologies, sample requirements, testing times, memory capacities and operating features. The three important systems covered in this Microsidd Knowledge Hub are: - **On Call Plus** – established blood glucose monitoring system. - **On Call Extra** – newer glucose monitoring platform with faster testing, smaller sample requirements and re-dosing capability. - **On Call GK Dual** – dual-purpose system capable of measuring blood glucose and blood β-ketones with the appropriate compatible strips. * * * ## On Call Plus Glucometer & Test Strips **On Call Plus** is one of the most widely recognised On Call glucose-monitoring systems. It uses its own compatible **On Call Plus Test Strips**. The traditional On Call Plus system uses approximately a **1 µL blood sample**, provides a result in approximately **10 seconds** and can store up to approximately **300 test results**. The system also uses a **code-chip based setup**, which is an important distinction from newer no-coding On Call platforms. ### Shop On Call Plus - [**On Call Plus Glucometer**](/products/oncall-plus-glucometer) - [**On Call Plus Complete Glucometer Kit**](/products/on-call-plus-glucometer-kit) - [**On Call Plus Test Strips 50**](/products/oncall-plus-glucometer-strips-50) - [**On Call Plus Test Strips 100**](/products/oncall-plus-glucometer-strips-100) - [**On Call Plus Test Strips 200 Hospital Pack**](/products/oncall-plus-glucometer-strips-hospital-pack) For all Plus products, visit the [**On Call Plus Glucometer & Test Strips Collection**](/collections/on-call-plus-glucometer-strips) . For a detailed product guide, read: [**On Call Plus Glucometer & Test Strips Complete Guide**](/blogs/knowledge-hub/on-call-plus-glucometer-test-strips-complete-guide) . * * * ## On Call Extra Glucometer & Test Strips **On Call Extra** is a newer ACON blood glucose monitoring system designed around a smaller blood sample and faster result time. According to ACON, the standard On Call Extra system requires approximately **0.4 µL of capillary whole blood** and provides a glucose result in approximately **4 seconds**. It uses no routine manual coding, stores up to approximately **500 results** with date and time and supports 7, 14, 30, 60 and 90-day averages. On Call Extra also provides a manufacturer-supported **re-dosing capability within approximately 3 seconds** when the initial blood application is insufficient. :contentReference\[oaicite:0\]{index=0} ### Shop On Call Extra - [**On Call Extra Blood Glucose Monitoring System**](/products/oncall-extra-glucometer) - [**On Call Extra Test Strips 50**](/products/oncall-extra-glucometer-strips) - [**On Call Extra Test Strips 100**](/products/oncall-extra-glucometer-strips-100) - [**On Call Extra Foil-Packed Test Strips**](/products/on-call-extra-glucometer-foiled-test-strips) Browse the [**On Call Extra Glucometer & Test Strips Collection**](/collections/on-call-extra-glucometer-strips) . Or read the [**On Call Extra Glucometer & Test Strips Complete Guide**](/blogs/knowledge-hub/on-call-extra-glucometer-test-strips-complete-guide) . * * * ## On Call GK Dual Glucose & Ketone Monitor The **On Call GK Dual** is different from the Plus and Extra systems. It is designed to perform **two different types of testing on one meter: blood glucose and blood β-ketones**. For glucose testing, ACON specifies compatibility with **On Call Chosen** or **On Call Advanced** glucose test strips. For β-ketone testing, the system uses **On Call Blood Ketone Test Strips**. These strip types are not interchangeable with On Call Plus or On Call Extra strips. :contentReference\[oaicite:1\]{index=1} ### On Call GK Dual Specifications Feature Glucose Testing β-Ketone Testing Approx. result time 5 seconds 10 seconds Approx. sample size 0.8 µL 1.2 µL Compatible strips On Call Chosen or On Call Advanced On Call Blood Ketone Test Strips The meter can store up to approximately **450 glucose and ketone records** with result type, date and time. :contentReference\[oaicite:2\]{index=2} ### Shop On Call GK Dual - [**On Call GK Dual Blood Glucose & Ketone Monitor**](/products/ketone-monitor) - [**On Call Blood Ketone Test Strips 25's**](/products/ketone-monitor-strips) For more information, read: [**On Call GK Dual Glucose & Ketone Monitor Complete Guide**](/blogs/knowledge-hub/on-call-gk-dual-glucose-ketone-monitor-complete-guide) . * * * ## On Call Plus vs Extra vs GK Dual Feature On Call Plus On Call Extra On Call GK Dual Primary function Blood glucose Blood glucose Blood glucose + β-ketone Compatible glucose strips On Call Plus On Call Extra On Call Chosen / Advanced Ketone testing No dedicated blood ketone strip system Glucose meter with ketone warning features Yes, using On Call Blood Ketone Test Strips Approx. glucose sample 1 µL 0.4 µL 0.8 µL Approx. glucose result time 10 sec 4 sec 5 sec Coding Code-chip based system No routine manual coding Follow compatible-strip instructions Approx. memory Up to 300 results Up to 500 results Up to 450 glucose/ketone records If you are deciding specifically between the two glucose-only systems, read: [**On Call Plus vs On Call Extra Glucometer: Complete Comparison →**](/blogs/knowledge-hub/on-call-plus-vs-on-call-extra-glucometer) * * * ## Are On Call Test Strips Interchangeable? **No. The On Call brand name alone does not establish strip compatibility.** The model name printed on the meter should match the appropriate compatible test-strip family. - **On Call Plus meter → On Call Plus Test Strips** - **On Call Extra meter → On Call Extra Test Strips** - **On Call GK Dual glucose testing → compatible On Call Chosen or Advanced strips** - **On Call GK Dual ketone testing → On Call Blood Ketone Test Strips** Before buying replacement strips, verify the exact meter name printed on the front or back of your meter. ### Compatibility Guides - [**On Call Plus Test Strip Compatibility Guide**](/blogs/knowledge-hub/on-call-plus-test-strips-compatibility-guide) - [**On Call Extra Test Strip Compatibility Guide**](/blogs/knowledge-hub/on-call-extra-test-strips-compatibility-guide) - [**On Call GK Dual Strip Compatibility Guide**](/blogs/knowledge-hub/on-call-gk-dual-strip-compatibility-guide) * * * ## How to Use an On Call Glucometer The exact operating procedure varies by model, but a typical blood glucose test includes: 1. Wash and thoroughly dry your hands. 2. Insert the correct compatible test strip into the meter. 3. Prepare the lancing device with a sterile lancet. 4. Obtain a blood drop according to the device instructions. 5. Apply blood to the test-strip sample area as directed. 6. Wait for the meter to display the result. 7. Dispose of used lancets and test strips appropriately. Always follow the instructions supplied with the exact meter and test-strip system you are using. - [**How to Use On Call Plus Glucometer & Test Strips**](/blogs/knowledge-hub/how-to-use-on-call-plus-glucometer-test-strips) - [**How to Use On Call Extra Glucometer & Test Strips**](/blogs/knowledge-hub/how-to-use-on-call-extra-glucometer-test-strips) * * * ## On Call Error Codes & Troubleshooting An error message does not necessarily mean that the meter has permanently failed. Errors can relate to strip insertion, sample application, batteries, temperature, coding or other operating conditions. **Do not assume that the same E-code has exactly the same meaning on every On Call model.** ### On Call Plus Error Codes On Call Plus users may encounter messages including **E0, E1, E2, E3, E4, E5, E6**, coding warnings, temperature warnings and other operating messages. Read: [**On Call Plus Error Codes & Troubleshooting Guide**](/blogs/knowledge-hub/on-call-plus-error-codes-troubleshooting-guide) . ### On Call Extra Error Codes On Call Extra users may encounter model-specific errors relating to strip handling, sample volume, batteries, temperature and meter operation. Read: [**On Call Extra Error Codes & Troubleshooting Guide**](/blogs/knowledge-hub/on-call-extra-error-codes-troubleshooting-guide) . ### On Call GK Dual Error Codes Because GK Dual operates with separate glucose and ketone strip systems, troubleshooting should account for the type of test being performed as well as the displayed meter message. Read: [**On Call GK Dual Error Codes & Troubleshooting Guide**](/blogs/knowledge-hub/on-call-gk-dual-error-codes-troubleshooting-guide) . You can also visit the broader [**Microsidd Glucometer Setup, Error Codes & Troubleshooting Guide**](/blogs/knowledge-hub/glucometer-setup-use-error-codes-troubleshooting) for general blood glucose meter troubleshooting. * * * ## On Call Plus Code Chip & Coding On Call Plus differs from newer no-coding systems because the traditional Plus platform uses a code-chip based system. When opening or changing compatible strip supplies, follow the coding instructions provided with the meter and strip packaging. A coding-related message should not be ignored by repeatedly inserting new strips. For detailed instructions, read: [**On Call Plus Code Chip & Coding Guide →**](/blogs/knowledge-hub/on-call-plus-code-chip-coding-guide) * * * ## On Call Extra Re-Dosing On Call Extra supports additional sample application within the manufacturer's specified short re-dosing window when the first application is insufficient. ACON specifies re-dosing capability within approximately **3 seconds**. :contentReference\[oaicite:3\]{index=3} This does not mean blood can be added indefinitely after testing has progressed. Follow the meter instructions and use a fresh strip when the meter instructs you to do so. Read: [**On Call Extra Re-Dosing & Second Blood Sample Guide →**](/blogs/knowledge-hub/on-call-extra-redosing-second-blood-sample-guide) * * * ## Understanding Glucose vs Ketone Testing with GK Dual Glucose and blood β-ketone testing measure different substances and require the appropriate test strip. The GK Dual meter identifies the test according to the compatible strip system being used. Users should never attempt to substitute a glucose strip for a ketone strip or vice versa. For a dedicated explanation, read: [**On Call GK Dual: Glucose vs Ketone Testing Guide →**](/blogs/knowledge-hub/on-call-gk-dual-glucose-vs-ketone-testing-guide) * * * ## On Call Test Strip Expiry & Storage Test strips are sensitive diagnostic consumables. Always follow the storage conditions and expiry information printed on the specific manufacturer packaging. General good practice includes: - Use strips only within the manufacturer's stated expiry period. - Keep strips in the packaging specified for that strip system. - Close strip containers promptly where applicable. - Protect strips from unsuitable heat, moisture and contamination. - Do not use strips that appear damaged or contaminated. Model-specific guides: - [**On Call Plus Test Strips Expiry & Storage Guide**](/blogs/knowledge-hub/on-call-plus-test-strips-expiry-storage-guide) - [**On Call Extra Test Strips Expiry & Storage Guide**](/blogs/knowledge-hub/on-call-extra-test-strips-expiry-storage-guide) - [**On Call GK Dual Ketone Test Strips Expiry & Storage Guide**](/blogs/knowledge-hub/on-call-gk-dual-ketone-strips-expiry-storage-guide) * * * ## On Call Plus Test Strips: 50 vs 100 vs 200 Microsidd offers multiple On Call Plus strip quantities to suit different testing frequencies. - **50 strips** – practical standard pack for many regular users. - **100 strips** – larger quantity for more frequent testing. - **200-strip hospital pack** – larger pack for higher-volume requirements. Before purchasing larger quantities, consider expected usage, storage conditions and the expiry date of the supplied batch. Read: [**On Call Plus Test Strips 50 vs 200 Pack Guide →**](/blogs/knowledge-hub/on-call-plus-strips-50-vs-200) * * * ## Which On Call Meter Should You Choose? The appropriate model depends on what type of testing and strip system you intend to use. ### Consider On Call Plus if: - You already use an On Call Plus meter. - You want continued compatibility with On Call Plus Test Strips. - You require access to larger Plus strip quantities. ### Consider On Call Extra if: - You want a smaller approximately 0.4 µL sample requirement. - You prefer an approximately 4-second glucose result. - You prefer a no-routine-manual-coding system. - You want the manufacturer's short re-dosing capability. ### Consider On Call GK Dual if: - You specifically need a system capable of both glucose and blood β-ketone testing. - You understand that separate compatible strip systems are required for glucose and ketone testing. For a direct comparison of the two main glucose systems, visit: [**On Call Plus vs On Call Extra Comparison**](/blogs/knowledge-hub/on-call-plus-vs-on-call-extra-glucometer) . * * * ## Why Buy On Call Glucometers & Test Strips from Microsidd? Microsidd India supplies diabetes monitoring products to individual customers, healthcare professionals, clinics and laboratories. - Genuine On Call / ACON products from established supply channels - On Call Plus, Extra and GK Dual product options - Multiple test-strip quantities - Competitive online pricing - Delivery across India - Fast fulfilment to major cities where serviceability permits - GST invoice available where applicable - Dedicated compatibility and troubleshooting information Shop the complete range: [**On Call Glucometers & Test Strips at Microsidd →**](/collections/on-call-glucometer-test-strips) Customers in Bengaluru can also learn more about [**Microsidd India, RT Nagar, Bengaluru**](/pages/microsidd-india-bangalore) . * * * ## Frequently Asked Questions ### Are On Call Plus and On Call Extra strips interchangeable? No. On Call Plus and On Call Extra use their respective compatible test-strip systems. Always match the strip family to the meter model. ### Can On Call GK Dual use On Call Plus strips? ACON specifies On Call Chosen or On Call Advanced test strips for glucose testing with GK Dual, rather than On Call Plus strips. :contentReference\[oaicite:4\]{index=4} ### Which strips are used to test ketones with On Call GK Dual? On Call GK Dual uses compatible On Call Blood Ketone Test Strips for β-ketone testing. :contentReference\[oaicite:5\]{index=5} ### Which is faster: On Call Plus or On Call Extra? The standard On Call Extra system provides a glucose result in approximately 4 seconds, while the traditional On Call Plus system takes approximately 10 seconds. ### How much blood does On Call Extra require? ACON specifies a minimum sample size of approximately 0.4 µL for the standard On Call Extra system. :contentReference\[oaicite:6\]{index=6} ### Does On Call Extra require coding? The standard current On Call Extra system uses a no-coding design with auto-code calibration circuitry in the strips. :contentReference\[oaicite:7\]{index=7} ### What does E1 or E2 mean on an On Call meter? Use the troubleshooting guide for your exact On Call model. Do not assume that an error number has identical troubleshooting instructions across Plus, Extra and GK Dual. ### Can I add more blood to an On Call Extra strip? ACON states that the Extra system supports re-dosing within approximately 3 seconds under the manufacturer's specified conditions. Follow the instructions supplied with the meter and strips. :contentReference\[oaicite:8\]{index=8} ### Where can I buy On Call Plus and Extra strips in India? Microsidd offers On Call glucose-monitoring products and compatible test strips online for delivery across India, subject to current product availability. * * * ## Related On Call Guides - [On Call Plus Glucometer & Test Strips Complete Guide](/blogs/knowledge-hub/on-call-plus-glucometer-test-strips-complete-guide) - [On Call Extra Glucometer & Test Strips Complete Guide](/blogs/knowledge-hub/on-call-extra-glucometer-test-strips-complete-guide) - [On Call GK Dual Glucose & Ketone Monitor Complete Guide](/blogs/knowledge-hub/on-call-gk-dual-glucose-ketone-monitor-complete-guide) - [On Call Plus vs On Call Extra Comparison](/blogs/knowledge-hub/on-call-plus-vs-on-call-extra-glucometer) - [On Call Plus Error Codes & Troubleshooting Guide](/blogs/knowledge-hub/on-call-plus-error-codes-troubleshooting-guide) - [On Call Extra Error Codes & Troubleshooting Guide](/blogs/knowledge-hub/on-call-extra-error-codes-troubleshooting-guide) - [On Call GK Dual Error Codes & Troubleshooting Guide](/blogs/knowledge-hub/on-call-gk-dual-error-codes-troubleshooting-guide) * * * **Medical information notice:** This guide is intended to explain product features, compatibility, operation and purchasing information. It does not interpret individual glucose or ketone results and does not replace medical advice. Follow the instructions supplied with the specific meter and test strips, and consult an appropriate healthcare professional regarding testing frequency, target ranges or treatment decisions. **Tags:** knowledge hub, On-Call Extra Glucometer, On-Call Extra Glucometer Strips, On-Call GK Dual Ketone Strips, On-Call GK Dual Monitor, On-Call Glucometers & Strips Complete Guide, On-Call Ketone Strips, On-Call plus Glucometer, On-Call Plus Glucometer Strips --- > Source: [Microsidd India](https://microsidd.com/blogs/knowledge-hub/on-call-glucometers-test-strips-complete-guide)