Secure Meters Ltd. Offers Programmable Digital Meter. Secure Meters Ltd. Is an ISO: 27001 and ISO: 14000 certified company. Programmable Digital Meter is available as `I-Credit 300`. It is used for measurement of electrical energy in single phase 2-wire networks. It provides an affordable solution for dynamic metering requirements through comprehensive and advanced functionality. The Programmable Digital Meter is applied in single phase industrial or commercial load, billing and revenue management.