# How to Use On Call Extra Glucometer & Test Strips: Step-by-Step Guide

**By Dr Pramod kumar** · 2026-09-25

The **On Call Extra Blood Glucose Monitoring System** is designed for blood glucose testing using compatible **On Call Extra Test Strips**. Correct strip insertion, sample application and timing are important for completing a glucose test successfully.

The standard On Call Extra system uses approximately **0.4 µL of fresh capillary whole blood** and displays a result in approximately **4 seconds** after the meter accepts an adequate sample.

This guide explains **how to use the On Call Extra glucometer step by step**, including strip insertion, lancing, blood application, the approximately 3-second re-dosing feature, result reading, strip ejection and common testing errors.

For the complete On Call Extra overview, read: [**On Call Extra Glucometer & Test Strips Complete Guide**](/blogs/knowledge-hub/on-call-extra-glucometer-test-strips-complete-guide) .

To shop compatible meters and strips, visit: [**On Call Extra Glucometer & Test Strips Collection**](/collections/on-call-extra-glucometer-strips) .

* * *

## Before Using the On Call Extra Glucometer

Before testing, make sure you have:

-   On Call Extra blood glucose meter
-   Compatible On Call Extra Test Strip
-   Lancing device
-   New sterile lancet
-   Clean, dry hands
-   Suitable disposal method for the used lancet

The standard On Call Extra system does **not require routine manual coding**. ACON describes the strips as using automatic calibration circuitry. :contentReference\[oaicite:1\]{index=1}

If you are unsure whether your strips are correct, read:

[**On Call Extra Test Strip Compatibility Guide →**](/blogs/knowledge-hub/on-call-extra-test-strips-compatibility-guide)

* * *

## On Call Extra Testing: Quick Overview

Step

What to Do

1

Wash and thoroughly dry your hands.

2

Confirm you have an On Call Extra Test Strip.

3

Insert the strip contact-bars first and facing up.

4

Wait for the blood-drop / strip-ready symbol.

5

Prepare the lancing device with a new sterile lancet.

6

Obtain an adequate blood drop.

7

Touch the blood drop to the sample tip of the strip.

8

Allow the check window to fill.

9

If needed, re-dose within about 3 seconds before countdown begins.

10

Wait approximately 4 seconds for the result.

11

Review the result.

12

Use the strip ejector or remove the used strip safely.

* * *

## Step 1: Wash and Dry Your Hands

Wash your hands with soap and water before testing and dry them thoroughly.

Clean hands help reduce the chance that food residue, sugar-containing substances or other contaminants on the skin will affect the blood sample.

Thorough drying is also important because excess water on the fingertip can dilute the sample.

* * *

## Step 2: Confirm You Have the Correct On Call Extra Test Strips

Before inserting a strip, check that the packaging specifically identifies the product as **On Call Extra Blood Glucose Test Strips**.

Do not use strips merely because they carry the On Call brand name.

-   **On Call Extra → On Call Extra Test Strips**
-   **On Call Plus → On Call Plus Test Strips**
-   **GK Dual → its specified glucose or ketone strip systems**

For detailed compatibility guidance:

[**On Call Extra Test Strip Compatibility Guide →**](/blogs/knowledge-hub/on-call-extra-test-strips-compatibility-guide)

* * *

## Step 3: Insert the Test Strip Correctly

Insert a fresh On Call Extra Test Strip into the strip port with the **contact-bar end first and facing upward**.

Push the strip into the meter until it stops.

Inserting a new strip normally turns the meter on and automatically enters test mode. :contentReference\[oaicite:2\]{index=2}

If the strip is inserted incorrectly, the meter may not turn on or recognise the strip.

* * *

## Step 4: Wait for the Blood-Drop / Strip Symbol

After the strip has been inserted, wait until the meter displays the **blood-drop / strip-ready symbol**.

Do not apply blood before this indication appears.

Applying the sample too early can cause an **E-3 error**. :contentReference\[oaicite:3\]{index=3}

* * *

## Step 5: Prepare the Lancing Device

Insert a **new sterile lancet** into the lancing device according to the lancing-device instructions.

Adjust the penetration depth as appropriate for your skin and the device being used.

A lancet should not be shared between people.

* * *

## Step 6: Obtain a Blood Drop

Use the prepared lancing device to obtain a fresh capillary blood drop.

The standard On Call Extra system requires approximately **0.4 µL of blood**. :contentReference\[oaicite:4\]{index=4}

The drop should be large enough to fill the strip's sample channel and check window correctly.

* * *

## Step 7: Apply Blood to the Sample Tip

Touch the blood drop to the **sample tip at the end of the test strip**.

The strip automatically draws the blood into the reaction cell.

**Do not apply blood to the top, front or back surface of the strip.** The manufacturer specifically instructs users to apply the sample only to the sample tip. :contentReference\[oaicite:5\]{index=5}

* * *

## Step 8: Fill the Check Window

Keep the blood drop in contact with the strip sample tip until the **check window is completely filled**.

When an adequate sample has been accepted, the meter begins its countdown.

The check window provides a visual way to confirm that sufficient sample has entered the strip. :contentReference\[oaicite:6\]{index=6}

* * *

## Step 9: Use Re-Dosing Only When Needed

On Call Extra has a useful model-specific feature: **a second blood drop may be applied within approximately 3 seconds** when the first application is insufficient and the countdown has not begun.

This can help avoid wasting a strip when the initial sample is slightly too small.

However, this is a short and specific re-dosing window.

For complete guidance:

[**On Call Extra Re-Dosing & Second Blood Sample Guide →**](/blogs/knowledge-hub/on-call-extra-redosing-second-blood-sample-guide)

* * *

## When Should You NOT Add More Blood?

Once the meter has started its countdown, do not continue adding more blood.

If the check window is not completely filled but the meter has already begun counting down, the manufacturer instructs users to discard the strip and repeat the test with a new one.

Adding more blood after the countdown has started can produce an **E-5 error or an inaccurate result**. :contentReference\[oaicite:7\]{index=7}

* * *

## Step 10: Wait for the Result

Once an adequate sample has been accepted, the On Call Extra meter typically provides the glucose result in approximately **4 seconds**. :contentReference\[oaicite:8\]{index=8}

Do not remove the strip while the meter is counting down.

Removing the strip during testing can result in an **E-2 error**.

* * *

## Step 11: Read the Glucose Result

The result appears on the meter display after the countdown is complete.

The standard On Call Extra system has a documented measurement range of approximately **10–600 mg/dL**. :contentReference\[oaicite:9\]{index=9}

A numerical glucose result should be interpreted according to the target range and treatment plan given to you by an appropriate healthcare professional.

* * *

## What Does HI Mean?

A **HI** display means the glucose concentration is above the meter's approximately **600 mg/dL upper measurement limit**. :contentReference\[oaicite:10\]{index=10}

Follow the manufacturer instructions for repeat testing with a fresh strip. If HI is confirmed, seek prompt medical advice.

* * *

## What Does LO Mean?

A **LO** display means the measured glucose concentration is below the meter's approximately **10 mg/dL lower measurement limit**. :contentReference\[oaicite:11\]{index=11}

A repeated LO result can indicate severely low blood glucose. Follow your healthcare professional's emergency guidance and seek urgent medical help when appropriate.

* * *

## Step 12: Remove the Used Test Strip

The standard On Call Extra meter includes a **built-in test-strip ejector**. :contentReference\[oaicite:12\]{index=12}

After testing is complete, use the ejector as instructed to release the used strip without unnecessarily handling the blood-exposed strip at the meter port.

Dispose of the strip according to appropriate local hygiene and waste practices.

* * *

## Step 13: Dispose of the Used Lancet Safely

Used lancets are sharps contaminated with blood.

Dispose of them according to applicable local sharps-disposal guidance. Do not leave exposed used lancets in ordinary open household waste where someone could be injured.

* * *

## How Much Blood Does On Call Extra Need?

The standard On Call Extra system requires approximately **0.4 µL** of fresh capillary whole blood.

If too little sample reaches the strip, the check window may not fill and the meter may fail to begin the countdown or may produce an E-5 message.

* * *

## Where Exactly Should Blood Be Applied?

Apply blood to the **sample tip** of the On Call Extra strip.

Do not:

-   smear blood across the strip,
-   apply blood to the top surface,
-   apply blood to the back of the strip, or
-   press the fingertip directly against the strip.

These warnings are specifically included in the manufacturer's strip instructions. :contentReference\[oaicite:13\]{index=13}

* * *

## How Do I Know If Enough Blood Has Been Applied?

Check that the strip's **sample check window is fully filled**.

The meter should then begin its countdown.

If the countdown does not begin, the sample may be insufficient and the Extra-specific re-dosing window may still be available.

* * *

## What Is Audible Fill Detection?

On Call Extra includes **audible fill detection**, which helps signal that the strip has received the sample as required. :contentReference\[oaicite:14\]{index=14}

This feature complements the visual check window but does not replace correct sample application.

* * *

## Why Is My On Call Extra Showing E3?

**E-3** generally means that blood or control solution was applied before the meter was ready.

Use a fresh strip and wait for the blood-drop / strip symbol before applying the sample.

* * *

## Why Is My On Call Extra Showing E5?

**E-5** can occur when:

-   the sample is insufficient, or
-   additional blood is applied too late.

If the initial sample is too small and the countdown has not started, use the manufacturer's short re-dosing window.

If the countdown has already begun, do not add more blood.

For detailed troubleshooting:

[**On Call Extra Error Codes & Troubleshooting Guide →**](/blogs/knowledge-hub/on-call-extra-error-codes-troubleshooting-guide)

* * *

## Why Is My On Call Extra Not Reading the Strip?

Check:

-   that the strip is genuinely intended for On Call Extra,
-   that the contact-bar end is inserted first,
-   that the strip is facing upward,
-   that it is fully inserted,
-   that it is new and undamaged,
-   that it is within expiry, and
-   that the meter battery has sufficient power.

If an error code appears, note the exact code before discarding the strip.

* * *

## Can On Call Plus Strips Be Used?

No.

On Call Plus and On Call Extra use separate compatible strip families.

Use:

**On Call Extra meter → On Call Extra Test Strips.**

For more detail:

[**On Call Extra Test Strip Compatibility Guide →**](/blogs/knowledge-hub/on-call-extra-test-strips-compatibility-guide)

* * *

## Can I Use Individually Foil-Packed On Call Extra Strips?

Yes, where the product is specifically identified as compatible with the On Call Extra system.

The individual foil packaging changes how each strip is stored before use, not the basic Extra testing procedure.

[**Shop On Call Extra Individually Foil-Packed Test Strips →**](/products/on-call-extra-glucometer-foiled-test-strips)

* * *

## How to Store On Call Extra Test Strips

Always follow the storage instructions printed on the actual strip product. The On Call Extra instructions specify cool, dry storage and protection from heat, direct sunlight and unsuitable environmental conditions.

For applicable Extra strips, manufacturer documentation describes storage at approximately **2–30°C** and states that strips should not be refrigerated or frozen. :contentReference\[oaicite:15\]{index=15}

For detailed handling and expiry information:

[**On Call Extra Test Strips Expiry & Storage Guide →**](/blogs/knowledge-hub/on-call-extra-test-strips-expiry-storage-guide)

* * *

## When Should You Perform a Control Solution Test?

A control solution test helps confirm that the meter and strips are working together properly and that the test procedure is being performed correctly.

The On Call Extra manual recommends quality-control testing in circumstances such as before first use and when system performance is in question. :contentReference\[oaicite:16\]{index=16}

A control result should be compared with the applicable control range printed for the strip product.

Control solution results are not personal blood glucose readings.

* * *

## Common On Call Extra Testing Mistakes

Mistake

Possible Result

Using On Call Plus strips

Compatibility or strip-recognition problem

Applying blood before sample-ready symbol

E-3 error

Using a previously used strip

E-4 error

Using too little blood

E-5 or no countdown

Adding second blood drop too late

E-5 or unreliable result

Removing strip during countdown

E-2 error

Applying blood to top of strip

Incorrect sample application

Using damaged or expired strip

Error or unreliable testing

* * *

## On Call Extra vs On Call Plus: Testing Procedure Differences

Feature

On Call Plus

On Call Extra

Approx. sample size

1 µL

0.4 µL

Approx. result time

10 seconds

4 seconds

Routine manual coding

Code-chip based

No

Re-dosing feature

Follow Plus-specific instructions

Second drop within about 3 seconds when permitted

Strip ejector

Follow Plus configuration

Built-in ejector on standard Extra meter

For the detailed comparison:

[**On Call Plus vs On Call Extra Glucometer →**](/blogs/knowledge-hub/on-call-plus-vs-on-call-extra-glucometer)

* * *

## On Call Extra Test Strip Pack Options

-   [**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 Individually Foil-Packed Test Strips**](/products/on-call-extra-glucometer-foiled-test-strips)

For pack comparison:

[**On Call Extra 50 vs 100 vs Foil Pack Guide →**](/blogs/knowledge-hub/on-call-extra-strips-50-vs-100-vs-foil-pack)

* * *

## Frequently Asked Questions

### How do I start an On Call Extra glucose test?

Insert a fresh compatible On Call Extra Test Strip contact-bars first and facing upward. Wait for the blood-drop / strip-ready symbol before applying blood.

### How much blood does On Call Extra need?

The standard system requires approximately **0.4 µL**.

### Where should I apply the blood?

Apply the blood drop only to the **sample tip** at the end of the strip. Do not apply blood to the top or back of the strip.

### How long does On Call Extra take?

The result is typically displayed in approximately **4 seconds** after an adequate sample is accepted.

### Can I add a second drop of blood?

Yes, under the manufacturer-specified conditions. If the first sample is insufficient and the countdown has not started, an additional drop may be applied within approximately 3 seconds.

### Can I add blood after the countdown starts?

No. If the check window is not properly filled but the meter has already begun counting down, discard the strip and repeat with a new one. Adding blood late can cause E-5 or an inaccurate result.

### Does On Call Extra require coding?

The standard Extra system uses automatic strip calibration and does not require routine manual coding.

### Why does the meter show E3?

E-3 generally means blood or control solution was applied before the meter was ready.

### Why does the meter show E5?

E-5 can indicate insufficient sample or late re-dosing.

### Can I use On Call Plus strips?

No. Use compatible On Call Extra Test Strips with an On Call Extra meter.

### Can I use foil-packed Extra strips?

Yes, when the product is specifically identified as compatible with the On Call Extra system.

### What does HI mean?

HI indicates a glucose concentration above the meter's approximately 600 mg/dL upper reportable range.

### What does LO mean?

LO indicates a glucose concentration below the meter's approximately 10 mg/dL lower reportable range.

* * *

## Related On Call Extra Guides

-   [On Call Extra Glucometer & Test Strips Complete Guide](/blogs/knowledge-hub/on-call-extra-glucometer-test-strips-complete-guide)
-   [On Call Extra Test Strip Compatibility Guide](/blogs/knowledge-hub/on-call-extra-test-strips-compatibility-guide)
-   [On Call Extra Error Codes & Troubleshooting Guide](/blogs/knowledge-hub/on-call-extra-error-codes-troubleshooting-guide)
-   [On Call Extra Re-Dosing & Second Blood Sample Guide](/blogs/knowledge-hub/on-call-extra-redosing-second-blood-sample-guide)
-   [On Call Extra Test Strips Expiry & Storage Guide](/blogs/knowledge-hub/on-call-extra-test-strips-expiry-storage-guide)
-   [On Call Extra Test Strips 50 vs 100 vs Foil Pack](/blogs/knowledge-hub/on-call-extra-strips-50-vs-100-vs-foil-pack)
-   [On Call Plus vs On Call Extra Glucometer Comparison](/blogs/knowledge-hub/on-call-plus-vs-on-call-extra-glucometer)
-   [On Call Plus, Extra & GK Dual Complete Guide](/blogs/knowledge-hub/on-call-glucometers-test-strips-complete-guide)

* * *

## Shop On Call Extra at Microsidd

-   [**On Call Extra Glucometer Kit**](/products/oncall-extra-glucometer)
-   [**On Call Extra Glucometer Without Strips**](/products/oncall-extra-glucometer-without-strips)
-   [**On Call Extra Test Strips 50**](/products/oncall-extra-glucometer-strips)
-   [**On Call Extra Test Strips 100**](/products/oncall-extra-glucometer-strips-100)

View the full range: [**Shop On Call Extra Glucometers & Test Strips →**](/collections/on-call-extra-glucometer-strips)

* * *

**Medical information notice:** This article explains the general operating procedure for the On Call Extra Blood Glucose Monitoring System. It does not replace the user manual supplied with your exact meter and test strips and does not diagnose diabetes or interpret whether an individual glucose result is clinically safe.

Follow the manufacturer's instructions for testing, strip handling, sample application, re-dosing and control checks. Your healthcare professional should determine your glucose targets, testing frequency and treatment plan.

If a result is unexpectedly high or low, repeat testing according to the manufacturer's instructions where appropriate. Repeated **HI or LO** results, severe symptoms, confusion, loss of consciousness or inability to self-treat require prompt medical assessment. Do not delay necessary medical care while troubleshooting the meter.

**Tags:** MicroSidd On Call Extra, On Call Extra Error Codes & Troubleshooting Guide, On Call Extra Glucometer & Test Strips Complete Guide, On Call Extra strips online, On Call Extra Test Strip Compatibility Guide, On Call Plus vs On Call Extra glucometer and test strips comparison

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> Source: [Microsidd India](https://microsidd.com/blogs/knowledge-hub/how-to-use-on-call-extra-glucometer-test-strips)