Vaccine Storage & ILR Temperature Monitoring (WHO PQS, UIP)

Under India's Universal Immunisation Programme (UIP), vaccines move from government medical store depots to state, regional and district vaccine stores and on to PHCs, CHCs and urban health posts. At most of these cold chain points the storage equipment is the same pair: an ice-lined refrigerator that holds vaccines at 2–8 °C, and a deep freezer that runs at -15 to -25 °C to freeze ice packs and store the vaccines that tolerate freezing.

An ILR is built to ride through power cuts. Its ice lining keeps the cabinet cold for many hours without electricity, which is why it is the standard vaccine refrigerator where the grid is unreliable. The same design makes the bottom of the cabinet the coldest spot, and freezing, not heat, is the most common way vaccines are damaged in an ILR. Freeze-sensitive vaccines should never touch the floor or the walls.

For monitoring, that means one probe per unit, placed where the vaccines are, not where it is easiest to fit. In an ILR the probe belongs in the vaccine basket at the level of the freeze-sensitive stock. In a deep freezer it sits among the ice packs. A dual-channel logger such as the IBI-MTD120 covers an ILR and its neighbouring deep freezer with one device and one power point, with separate limits for each.

A 30 DTR (30-day temperature recorder) is a small battery-powered device placed in the ILR or freezer. It records the temperature at short intervals, stores a rolling 30-day history and shows an alarm on its own display when the unit has been too warm or too cold for a set time. It is the minimum record the programme expects at a cold chain point, and it is read and noted by the vaccine handler.

The weakness of a 30 DTR is that it only speaks to the person standing in front of it. A continuous remote logger sends the same kind of reading to a cloud dashboard every 15 minutes by default, raises a live alert, app notification or optional SMS the moment a limit is crossed, and keeps a complete history beyond 30 days. The recorder stays in the ILR as the local reference; the remote logger makes sure somebody acts before the vaccines are lost.

WHO's Performance, Quality and Safety (PQS) system groups temperature monitoring devices under category E006, which covers 30-day recorders, remote temperature monitoring devices and related equipment. The specifications cover measurement accuracy, alarm behaviour, data retention, battery life and robustness. UNICEF and many national programmes buy against these specifications.

Ideabytes loggers are designed with those expectations in mind: ±0.5 °C accuracy between -10 °C and +50 °C, 0.1 °C resolution, configurable intervals, alarm logs and an audit trail. Ask us for the documentation of the specific model you are considering; our compliance page explains what WHO PQS listing does and does not mean for a buyer.

At a PHC the most dangerous event is a long power cut that nobody reports. Ideabytes 4G loggers carry a built-in M2M SIM and an internal lithium-ion battery that keeps them running for up to 20 hours after mains power fails (up to 30 hours on the IBI-MT70). They keep reading the ILR and send a power-failure alert, so the medical officer knows to arrange a generator or move vaccines while the ice lining still holds.

India runs eVIN (Electronic Vaccine Intelligence Network) as the national system for vaccine stock and cold chain temperature visibility across UIP cold chain points. Ideabytes loggers are not part of eVIN and we do not claim integration with it. Programme teams and hospitals use our loggers where they need an independent, alarm-driven record: in hospital immunisation clinics, in private facilities outside eVIN, in state or city pilots, or as an additional layer at high-value stores.

Private hospitals, paediatric clinics and travel vaccination centres usually store vaccines in a purpose-built pharmacy refrigerator rather than an ILR, but the monitoring need is identical: a continuous 2–8 °C record, alerts to the person in charge and a report the auditor can read. A Wi-Fi logger suits a single clinic; a 4G logger suits a chain with branches across a city.

Government buyers can purchase through GeM, where Ideabytes IoT is registered, or through a tender. For a tender, share the technical specification and we will respond with a compliance statement, datasheets and NABL-traceable calibration certificates. Cost depends on the number of cold chain points, the mix of ILRs and freezers, connectivity and the reporting subscription.