In my time as an engineer at Network Rail I have been using several the products manufactured by T&R Test Equipment Ltd. The 200ADM-P is a useful and flexible Secondary Injection / Relay test set, with a main and aux channel offering phase shifting current and voltage it can test most of the common relays I came across. In the metal case it has a small and light profile but is very robust and the inbuilt protection great.
Richard CatlowSNC-Lavelin